(1) Disruptive Effects: If the victim is almost in contact with a large bomb he may be blown to pieces, e.g., when the victim is carrying it. The pieces can be scattered over an area of 200 metres radius. Many parts of the body are never found, having been disrupted into tiny fragments and mixed with the masonry and other debris of the bomb site. A bomb exploding on the ground may cause severe damage or traumatic amputation of the lower legs. A bomb which explodes when the victim is bending over it, may cause severe damage to arms, face and front of the chest. When the victim is a few metres away or with smaller explosion, disruption is usually limited to mutilation of a localised area.

(2) Burns: The temperature of the explosive gases can exceed 2000°C., and the radiated heat can cause flash bums. It bums nearby objects and clothing. The flame causes extensive bums, which involve irregular area of skin to a different degree. Tight clothing protects, so that beneath collars, bras, waist bands, socks and shoes the skin may be quite normal.

(3) Air Blast: An explosion produces a ‘shock wave’ which spreads concentrically from the site of explosion at about the speed of sound (1 l20ftJsec). This wave of very high pressure is followed by a weak wave of negative pressure (below atmosphere), a suction which lasts about five times as long. A shock wave exceeding 700 kilopascals (100 lb/sq. inch) pressure is necessary to cause serious damage to a body. The shock wave can throw the victim against a wall or toss him through the air causing blunt force injuries. The clothes may be blown off by the blast. The clothing should be retained for chemical analysis. The shock wave passes through the body. The homogeneous tissues like liver and muscle are not damaged.

Blast injury of lungs is seen if the victim is within a few metres of explosion, and at such range, the victim usually dies from other injuries. Lungs show subpleural patchy haemorrhages, scattered at random, often in the line of ribs. Sectioning of lungs shows more discrete scattered areas of haemorrhage, often with a tendency to be more central than periphery. Microscopically, alveolar ruptures, thinning of alveolar septae, enlargement of alveolar spaces and circumscribed subpleural, intra-alveolar and perivascular haemorrhages are the main findings.

Desquamated alveolar and bronchial epithelium is seen lying free. This causes reactive pulmonary oedema and bloodstained froth is found in the air-passages, and later bronchopneumonia. This specific pulmonary injury of air blast is called ‘blast lung’. The tympanic membrane may rupture with haemorrhage in the ear. Damage to cochlea is more frequent. Subperitoneal haemorrhage and haemorrhages in mesentery and omentum vary in size and laceration of abdominal organs may occur. Intracranial haemorrhage, contusion of the brain, injuries of heart and aorta, pneumothorax, ruptured stomach and bowel may occur.

Death may occur from systemic air embolism, from air which enters the pulmonary veins after blast damage to the lungs. When the explosion is in the water, the pressure changes are called underwater blast. The physical changes are similar to those of explosion in air. Injuries occur mostly in gastrointestinal tract and less commonly in lungs. Most of the lung injury is due to pressure transmitted from abdomen through the diaphragm.

Solid blast refers to a wave of energy that spreads through a rigid structure when an explosive is detonated near it and people in contact with its structure can be injured. Steel construction of tanks and warships conduct shock wave well and cause solid blast injury. The injuries are mostly skeletal. The fractures depend on the position of the person. Fractures of legs and vertebral column are more common. Gastrointestinal damage is more common than lung damage. In some cases, death may occur without any external injury.

(4) Flying Missiles : The blast may drive multiple fragments of bomb or pieces of nearby objects, e.g., gravel, glass, wood, brick, plaster, etc. through the air into the skin and cause bruises, abrasions and puncture lacerations intimately mixed on the skin. This triad of injury is diagnostic. Most of the bruises and abrasions are less than one cm. in diameter, although they tend to unite. The puncture-lacerations are also usually of this size. They are ragged, sometimes with soiled margins, and may contain foreign material, such as scraps of clothing, wood or metal. The skin can be darkened by an explosion which drives dust into the skin and causes fairly uniform tattooing. The force of the bomb explosion is extremely directional and the pattern of injury might indicate that the person was carrying the bomb or bending over it or sitting to one side of it.

(5) Falling Masonry: When a building is destroyed by a bomb blast, the persons inside sustain multiple injuries and die of traumatic asphyxia.

(6) Fumes: If a bomb explodes in a confined space, enough CO is produced to cause asphyxia. In a victim of bomb death, X-rays of tissues should be taken, as pieces of metal especially the detonating mechanism may be seen.

Incendiary bombs, e.g., napalm bombs primarily cause burns. A temperature of about 10000 C is produced. In incendiary bombs, usually phosphorus and magnesium are added. The Molotov cocktail is an incendiary bomb which is thrown by the hand. In a crude type of this bomb, a bottle is filled with gasoline and a rag to serve as a wick. The wick is lighted and thrown at the target. Various acids and chemicals are sometimes added to increase the destructive effects.

BOMBING INCIDENTS INVESTIGATION

(1) Whether the explosion was caused by a bomb? Dispersed explosion usually occurs in houses when domestic gas leaks into the atmosphere and mixes with the air to form an explosive mixture that then catches fire. A dispersed explosion can blow off clothing and burn the exposed skin. All the exposed parts of the body are affected and all the burns are of same depth.

A bomb explosion (localised explosion) never causes extensive burns. Injuries by blast force, and the fragments are seen on the body. A part of a limb is blown off or a localised area of the body is mutilated. The triad of bruises, abrasions and puncture-lacerations with tattooing of part of the body also indicate bomb explosion.

(2) Identification of the dead.

(3) Number of dead persons.

(4) Cause of Death: Death may result from multiple injuries, burns, shock or cerebral air embolism.

(5) Circumstances of Death: To differentiate the terrorist from the peaceful citizen, the reconstruction of the scene and the circumstances of the deaths from the autopsy findings are helpful. The injuries on the victims, particularly their type, severity and distribution are of much help.

(a) Explosive Force Declines Rapidly: Injury due to the explosive force itself is likely within a few metres of the bomb. With a terrorist bomb, when a person is blown to pieces he must have been in contact with it, i.e., either carrying the bomb, sitting with it or arming it. Persons can be injured by flying fragments and collapsing structures when at considerable distance from a terrorist bomb.

(b) Explosive Force is Highly Directional: The parts of the body directly exposed to explosive force only are injured. An explosion at ground level injures mainly lower legs and feet. When a person is in front of a bomb when it blows up, the face, chest, forearms, hands, inner thighs and the legs below the knees are injured, but the back of the body, the lower legs and face escape. If a person is bending down over the bomb, the face, chest, lower legs and hands are severely damaged. The legs may be blown ofT or the abdomen disrupted or the hands and arms torn away in the person who was planting the bomb. If the thigh, pelvic region and abdomen are damaged, the bomb may have been carried on the lap. If a parcel bomb is opened by a person sitting at a desk, his face, chest and hands are injured. If a bomb explodes behind a person sitting in a chair, injuries will be produced on the back of the legs below the knee and on the back of the trunk.

All bodies should be X-rayed before autopsy to identify any radio.opaque objects including those from the bomb mechanism, such as small springs or contacts from the timer or detonator.

DOMESTIC GAS EXPLOSIONS

They occur due to leaks in the gas supply. Natural gas explodes at concentrations in air between 5 to 15 percent. Ignition is usually caused by matches or candles, fires, sparking electric switches. The explosion is accompanied by a momentary flame that sets fire to furnishings. The air pressure usually rises to less than 10 psi, due to venting through broken windows and doors. Deaths are rare. The person can be thrown off their feet and injured. The damage is haphazard or diffuse. The flame singes hair and causes localised superficial burns of exposed surfaces. Most deaths occur when the building collapses and the victims are buried in the debris.

MECHANICAL EXPLOSION

Mechanical explosion occurs when a steam boiler bursts due to increased pressure. Heat and large volumes of gas are produced. The effects are similar to those of chemical explosion.

Is the injury caused by discharge of firearm?

Firearm wounds are recognised by the appearance of clothing and body entrance and exit wounds, the track of the bullet, and the presence of bullet or pellets and residual matter in the clothing or around entrance wound and in the tissues.

What kind of weapon fired the shot?

The kind of firearm can be determined by the size, shape and composition of the bullet, and examination of cartridge, shots and wad left in the body or found at the scene of the crime and the appearances of wounds. With the shotgun, the appearances of the wound are characteristic. In muzzle-loading gun, the wad consists of plug of paper or cloth; in breech-loading gun of circular discs of felt or cardboard, from which the bore of the gun can be determined. Stains on the clothes or skin may show whether black or smokeless powder was used, and microscopic and chemical examination of the stain is helpful in finding out the particular brand of powder. Evidence of recent fire can be made out for a few days, by examination of the weapon for mercury vapour. Spent cartridge contains residues of primer and detonator.

In firearm examination, the primary principles of identification are

1. determination of caliber and type
2. number of rifling grooves
3. width of rifling grooves
4. direction (left twist or right twist) of rifling grooves
5.   pitch (angle of the spiral) of rifling

These are used to determine whether a bullet could have been fired in a type or model of a gun or specific weapon. The bullets expand into the grooves in the rifling, sealing the barrel and prevent excess escape of gases ahead of the bullet. The firearms leave their signature on the cartridge case and on the bullet. With all rifled firearms, the bullet is slightly larger than the barrel, and as it passes through the barrel, its sides are marked by the rifling of the barrel (primary markings; class characteristics) and cause the bullet to rotate. Class characteristics (bar codes) are determined before manufacture of the gun and result from manufacturing specifications, design and dimensions.

The class characteristics in fired bullet identifications would be

1. caliber
2. number of lands and grooves
3. direction of twist of the rifling
4. rate of the twist of the rifling
5. width of the lands and grooves

They are most useful in identifying the make and model of gun involved. The surface of the bullet is also grooved by irregularities on the inner surface of the barrel itself (secondary markings; individual or accidental characteristics), which are specific for that particular weapon. These irregularities are produced by the sticking of the particles of the bullet to the bore when shots are fired and is known as ‘metallic fouling’.

Individual characteristics also result accidentally during manufacturing process, are usually microscopic in nature, and have random distribution. They are useful to identify one specific gun to the exclusion of all others “bullet fingerprinting”. Sometimes, lead bullets may carry weave pattern of cloth. The bullet found in the body known as crime bullet or exhibit bullet is compared under a comparison microscope, with one fired from the suspected weapon known as test bullet.

The suspected weapon is fired, using the same brand and type of ammunition into a box filled with cotton waste (bullet traps), a bag of rags, a sand bag, oiled saw-dust, blocks of ice, water tanks (bullet recovery tank) or against white blotting paper. Fresh pork skins, cleanly shaven are ideal for comparison with patterns on human skin. From the fired cartridge case, the calibre and type of cartridge and its manufacturer can be determined, from the shape and size of the case and the stampings on the case head.

Fired cartridge cases also may be identified with the firearm from which they were discharged by a study of the marks left on them by the weapon. They are:

1. The firing imparts its general shape, size and tooling imperfections, striking the primer in centrefire cartridges, or case rim in rim fire cartridge.
2. The internal pressure of firing, forces the soft brass head of the cartridge case against the breech face, which produces markings.
3. The extractor usually marks the rim of a cartridge case while withdrawing the cartridge from the chamber, but may also make marks as it slips over and engages the cartridge rim or at the time of disengaging the rim. The end of the extractor hook may produce. markings against the case wall next to the head.
4. The ejector strikes the rim or head of cartridge sharply during ejection and usually leaves a mark.
5. The magazine or clip may leave both class and individual markings. Lips of a magazine usually mark the rim edges of cartridges as they are stripped from it and chambered.
6. Imperfections at the edge or mouth of the chamber will also mark the cartridge case as it is moved into and out of the chamber in loading and extraction.

From what distance and direction was the shot fired?

The range of fire is determined by the presence or absence of the marks of smoke, flame, tattooing, etc., on or in the body of the victim. When the range is greater, it can be determined only approximately and with difficulty, from the nature of wounds and penetration. Test fire with suspect weapon using the same ammunition is useful for estimating the range.

The direction of the track depends upon the posture of the body at the time of impact. The direction of fire may be determined from the position of entrance and exit wounds and the track, bearing in mind the possibility of deflection of bullet and the different relationships of the parts of the body in movement.

Sections of the skin and subcutaneous tissues taken from transcutaneous portions of bullet wound may provide evidence as to direction and range of fire. Carbonisation, desiccation or recognition of particles of debris embedded in epidermis near the bullet hole may indicate close range of fire and may distinguish entrance and exit sites.. The findings of debris along the track and in laceration adjacent to it suggest fire at contact range. The range from which the weapon was fired can be estimated by lead deposits around the entry wound. Swelling and homogenisation of dermal collagen caused by heat of bullet, is more marked at the entrance than the exit site.

If multiple wounds of entrance and exit are present, could they have been produced by a single bullet?

This has been already described.

If multiple wounds are present, were they produced from the same or different weapons?

This is determined by examination of the wound and of the bullet, cartridge, shots, wad, etc.

When was the firearm discharged?

Tissue reaction to firearm injury is similar as for other types of injury. If black powder has been used, hydrogen sulphide may persist in the barrel for a few hours if breech is closed. The washing from barrels having discharged gunpowder are alkaline, contain nitrite, sulphate and thiosulphate. Smokeless powder leaves a dark grey deposit in the barrel of a recently discharged firearm. It forms a neutral solution with distilled water and contains nitrites and nitrates, but no sulphides. The mixture of gases of explosion has a peculiar smell, which can be noticed prominently up to 4 to 6 hours. After 24 hours no smell is experienced after the discharge of a gun. Due to backward escape of gases from a fired weapon, the hand of the person will receive gases which carry particles of unburnt powder.

(i) PARAFFIN TEST OR DERMAL NITRATE TEST: It detects gun powder residue (nitrates and nitrites). Melted paraffin is brushed on the surface of the hand. The wax is renoved and inner surface of wax cast is treated with diphenylamine or diphenylhenzidine reagent. A blue colour develops where residue is present. It is absolete.

(ii) HARRISON AND GILROY TEST : This test is not specific for firearm discharge residues, but only for certain elements or compounds to be found in such residues. This detects the presence of antimony, barium and lead. A cotton swab moistened with molar hydrochloric acid is used.

(iii) Neutron Activation Analysis: This chemical method is useful in identifying minute traces of elements present in the hair, nails, soil, glass pieces, paints, gunshot residues, drugs, etc. This is helpful when samples for comparison are available. It is based on the detection and measurement of characteristic radioisotopes formed by irradiation in a nuclear reactor. The atoms of the elements present in a specimen are bombarded with neutrons. Some of the nuclei of the atoms capture neutrons. Those atoms capturing neutrons become radioactive. The radioactivity is measured with a detector connected to an analyser. In firearm discharges, the residue from the suspect’s hand is removed for testing either by the ordinary paraffin cast or simply by swabbing the back of the hand with cotton-tipped swabs, moistened with 5% nitric acid. Ideally four cotton swabs should be used to swab both palms and the back of each hand, a fifth swab should be sent separately as a control. As gunshot residue comes out of the barrel, it is the hand that was used to hold the barrel and the one upon the trigger that is likely to give a positive result. Antimony, and copper from the primer are the components of residue which are detected.

(IV) ATOMIC ABSORPTION SPECTROSCOPY (AAS) AND FLAMELESS ATOMIC ABSORPTION SPECTROSCOPY (FAAS): They are suitable for measurement of antimony, barium and copper in gunshot residues. This analytical system utilises high temperatures to vapourise the metallic elements of the primer residues and to detect and quantitate them. NAA and AAS can aid in

1. identifying holes in clothing, tissues, wood, etc. as bullet holes, from the presence of lead, antimony, barium and copper,
2. determining range of fire from concentration pattern of antimony around the bullet hole,
3. determining common origin of bullet fragments of shotgun pellets found at different places, from the concentrations of lead, antimony, arsenic, copper and silver in these alloys,
4. determining from the presence of lead, antimony and barium on hands whether or not a person has fired a gun.

(V) SCANNING ELECTRON MICROSCOPE- ENERGY DISPERSIVE X-RAY ANALYSIS (SEM-EDXA): It is the most sophisticated tool which can detect most minute traces of gunshot residue (GSR) found on the body of suspect. As a gun is fired, the GSR comprising chemical substances that burn and produce gases providing the velocity for the bullet, and metals such as antimony, barium, copper, etc. are also sprayed out and get deposited on the hands, clothes and even on the face of the person. The investigator can conclusively prove if the weapon was used by the suspect with a negligible margin of error.

How long did the victim survive?

It depends on the cause of death, i.e., whether from shock and haemorrhage, injury to a vital organ or septic complications.

How much activity could the victim perform following the injury ?

This varies considerably depending on the site of injury and the organ involved. If the bullet destroys motor area, brain stem or cervical cord or if a gaping laceration of the heart or aorta is produced, the victim becomes immediately incapacitated. Death is instantaneous if medulla is involved. Sometimes, through-and -through bullet wounds of the brain or heart do not cause immediate disability and the person may be able to carry out voluntary acts. Wounds of the auricles are most rapidly fatal; wounds of the right ventricle come next and the wounds of the left ventricle are the least rapidly fatal. The amount and rapidity of blood loss will also help to form an opinion about the extent of physical activity that would be possible. In any injury to other parts of the body, the victim may be able to walk about.

Is it a case of homicide, suicide or accident?

In deciding the status of a particular case, all the available information should be obtained, including autopsy findings, the investigation of scene of death and the circumstances of the shooting. Each case will present its own problems.

(A) The position and direction of the wound:

These are very important. For suicide the sites of election are:

1. temple (about 60%)
2. centre of forehead
3. roof of mouth
4. midline behind the chin
5. left side or front of chest

A suicide using a revolver or pistol, usually shoots himself in the right temple region, the bullet passing almost horizontally or upwards and backwards through the head, and making its exit in the left parietal region. If the individual is lefthanded, left temporal region is selected. Occasionally, a right-handed person holds the weapon with the butt projecting backwards and the thumb on the trigger, in which case the direction may be different. Sometimes, the gun is put into the mouth, nose, ear or on the face or undersurface of the chin, and fired upward into the brain.

In some cases, the suicide interposes his hand between the pistol and his head, shooting himself through the palm of the hand. Suicidal wounds of the chest and abdomen are less common. On the chest, the gun is fired into the cardiac region in a backward direction with a slight deviation upwards or downwards either to the right or left. On the abdomen, the gun is fired into the epigastric region and produces perforations and lacerations of the upper abdominal viscera.

In rifle and shotgun, the butt is usually supported by ground nd the weapon is fired by hand into the head, or the butt is supported against a wall and fired into the chest or abdomen. The person may attach some string or cord to the trigger and tie the loose end to his foot, lie down and discharge the weapon through the roof of his mouth.

He may tie the cord to some firm structure and pull the barrel towards him, thus firing the weapon or he may press the trigger with a stick or some similar object. The presence of blood splashes on the hand which held the gun or the presence of an impression of the trigger or trigger guard on one or more fingers indicates suicide.

In homicide, a great variety of wounds can occur depending upon the circumstances. If there is a scuffle, some of the wounds may be from close range and the bullets may strike the body in various places and at different angles. If the victim runs, most of the entrance wounds will be on the back. If victim rushes at the assailant, the entrance wounds are on front of the body.

If the assailant is in a panic or under strong emotion, a number of shots may miss the target or graze the skin. Wounds about the sides and limbs are suggestive of murder, if accident is excluded, and wounds about the back, and back of head are strongly suggestive of murder. Premeditated, calculated homicide by shooting can occur in a variety of ways. In gang feuds, the victim may be surprised and shot by enemies at close range into the back of the head and neck, with the bullet tracks parallel or only slightly deviating.

(B) The nature of the entrance wounds: This is very important. A contact wound is possibly suicidal, unless found on a part of the body which is not easily reached by the deceased, e.g., back of the chest or neck. Suicides usually pull the clothes aside to expose the skin before shooting themselves. Bullets vertically entering fatal parts like heart or head, indicate suicide. Several methods (combined suicides) or several attempts of committing suicide e.g., hanging and shooting indicate suicide. A close or distant shot is rarely suicidal.

(C) The number of wounds : Multiple wounds are usually homicidal especially if they occur on the back or sides of the body or involve different regions of the body or are non-contact shots. Occasionally, multiple suicidal wounds are seen involving a single region like the temple, chest or abdomen or a combination of two different regions. When multiple suicidal wounds are fired serially, the injuries by the first shot do not incapacitate the victim immediately, enabling him to fire other bullets into his body. A bullet passing through the brain, causes immediate unconsciousness, but if bone is involved without injury to the brain or a large vessel, the person may retain consciousness and power of motion. A bullet passing through the chest or abdominal viscera, in some cases does not incapacitate the victim and he may be able to shoot himself again.

(D) The position of the weapon : In suicide and accident, the weapon is usually found at the scene of the crime; the gun may bear the victims fingerprints. The hand that fired the shot may show evidence of gunsmoke, powder deposits and traces of metals. With handguns, the effects of the components of a shot are commonly seen on the thumb, index finger and the area between them. Blood splashes may soil the gun and the hand, if the hand pulling the trigger is close to the wound. In cases of murder.weapon is usually not found near the victim. If the weapon is strongly grasped in the hand of the victim due to instantaneous rigor, it is a strong presumptive evidence of suicide. In some cases of homicide, the scene may be altered to simulate suicide in order to conceal the crime. The assailant after producing a contact wound on the anterior surface of the body or an accessible part of head, may place the weapon in the hand of the deceased. In such cases, the thumb is usually found under and not around the gun handle, and the weapon is not tightly grasped. If the gun has been tampered with after shooting, e.g., removing of empty cartridge and substituting of unexploded cartridge, causes confusion. The absence of weapon is not conclusive of murder, for it may be removed by a person passing the place or in some fatal cases, the deceased is able to walk considerable distance, leaving the weapon behind.

(E) Motive : When a person commits suicide, he usually has a motive, and he may leave a note or make preparations to kill himself.

(F) The Scene : Photographs of the scene, the body and the gun should be taken. Fingerprints on the weapon, doors, etc., are useful. If the gun is present at the scene, its position in relation to the body, its make, model, calibre, type of action and description of the ammunition should be noted. Any loose bullets found should be collected. If they are embedded in the walls, ceiling or furniture, they should be extracted and retained. The place in which the body is found, e.g., in a room in his own house, the state of the room, whether showing signs of struggle or not, the condition of the doors and windows whether locked or not, should be noted. If the body is found in the open, a search for footmarks and marks of struggle must be made.

(G) Sex: It is very rare for females to commit suicide by shooting, and rare for persons who are not used to firearms.

(H) Disposal of the body : If the body is removed from the place of shooting or if an attempt is made to dispose off the body, commission of crime becomes obvious.

Accidental Wounds : They are comparatively rare, and usually single. Most of the accidents are caused by carelessness or misuse. The technical reasons for accident are: (a) the construction of the weapon, (b) the absence of safety device, (c) the poor quality of the material used. Accidents occur when loaded weapons are handled carelessly or carried without safety catch, or when the victim slips while examining, loading or cleaning the weapon. The wounds are found on the front of the body, and frequently directed upwards. Sometimes, the victim is shot unintentionally by a person who is ignorant of firearms or careless in their use. Occasionally, when the police shoot on law breakers, an innocent bystander is struck by bullets.

Hunting accidents may result from (a) swinging the weapon through the line of hunters, (b) ricochetting bullets or pellets, (c) failing to unload the weapon when jumping over ditches, climbing fences or crawling through them, (d) failing to unload or uncock the weapon when it is carried or laid down. In case of a discharge caused by falling weapon, (a) the weapon or its muzzle will be some distance away from the body, and there cannot be a direct contact shot, (b) the weapon will show signs of force to allow a discharge, (c) marks will be found on the ground where the weapon dropped.

Faked Firearm Wounds : Firearm wounds are very rarely voluntarily inflicted for the purpose of attributing murder. They involve non-vital parts and are near wounds.

Identification by Flash : It is possible to distinguish features with the help of a discharge from a gun or pistol up to a distance of about 8 metres, but the details of features of clothing cannot be made out. Thus, if the assailant is well-known to the victim, identification is possible.

Bullet holes in the walls, floor, and ceiling or in the furniture should be photographed. Before undressing, the body should be photographed. After the clothes are removed, entrance and exit bullet holes should be photographed with identifying labels and rulers. The bullets, pellets, and wadding found in the body should be photographed. All areas likely to bear suspect’s fingerprints, such as door knobs, glassware and the weapon should be examined for fingerprints.

EVIDENCE FROM SCENE

Collect :

1. The gun.
2. Fired bullets.
3. Empty cartridge cases, shells and wads.
4. Hairs, fibers and bloodstains.
5. Objects struck by or containing spent bullets, e.g. wood, cement, etc.
6. Glass shattered by bullets.
7. Areas showing fingerprints and footprints.

EVIDENCE FROM SUSPECT

Collect:

1. Clothes with trace evidence.
2. Victim’s hair, clothing, fibers and blood.
3. Gunpowder and other evidence on the hands.
4. Gun used in the crime.
5.   Unspent ammunition and empty cartridges or shells.

AUTOPSY: Clothing may be forced into the tissues in shotgun wounds. Probes, fingers, etc. should not be introduced through the defects in the clothing, as the direction or distribution of fibers will be changed and cause confusion in deciding the entrance and exit of a bullet.

Number the entrance and exit wounds. In the case of multiple wounds, it is advisable to give a number to each wound, disregarding whether it was caused by entry or exit of a bullet. The clothes should be preserved carefully in clean brown paper or plastic bags and sent to Forensic Science Laboratory for testing. The powder grains adherent to clothing should be carefully removed with forceps and preserved in a glass vial, as they may be lost from the clothes due to rough handling.

Clothes should be folded in such a way, that the area of bullet holes and gunpowder soiling are not disturbed or contaminated. Infrared photography can be used to find out soot deposit on dark colored or black fabrics. Ordinary X-ray can be used to search for larger metallic fragments for elemental content.

Bullet Wounds

If there are multiple wounds, they should be numbered. On the body diagrams, the wounds should be drawn as they appear on the body including burning, blackening, tattooing, abrasion collar, etc. Photographs of the wounds should be taken. Bullet wounds must be described with care.

1. the exact location of each wound should be noted in relation to its distance from the top of the head or the sole of the foot,
2. mid line of the body,
3. a fixed anatomical landmark, e.g., “in the chest, 50 cm. below the top of the head, 8 cm. to the left of the mid-line and 2 cm. above the nipple”. The size and the exact appearance of the wound is not preserved after excision due to the cutting of the elastic fibres.

External Wound

(a) The character of the perforation, its shape (stellate, round, slit-like or irregular), and size should be noted. The hole in the skin should be carefully measured first, and then the abrasion collar and the powder pattern surrounding the borders of the entrance wound. Difference in the width of the abrasion collar at different points should be noted as they indicate the angle at which the bullet struck the skin. A circular wound requires only one diameter of measurements, e.g., the skin perforation is round and measured 8 mm. in width. It is surrounded by a uniform rim abrasion 2 mm. in width. An elliptical wound is measured across its widest and narrowest diameters and variations in width of abrasion recorded, e.g., the skin perforation measured 8 mm. by 3 mm. with the larger diameter running horizontally. A rim abrasion measuring from 0.5 mm. to 2 mm. surrounds the skin perforation with the wider area located at its lateral side.

(b) The presence or absence of blackening and tattooing should be specifically noted, e.g., blackening and tattooing are absent, or the skin perforation is surrounded by an area of blackening and tattooing measuring 8 cm. by 5 cm. with the larger diameter running vertically.

(c) Skin splits, contiguous and non-contiguous.

(d) Muzzle imprint.

(e) Soot deposit, including the corona.

(f) Metal deposition.

Alteration by medical care personnel. A scaled photograph or a diagram showing the numbered wounds is useful. It is advisable to record the wound in the skin and the wound track through the body in one section. If the entrance wound is soiled with blood, it should be sponged carefully so that any tattooing of the skin may not be disturbed. After the wound has been examined, the skin around the entrance and exit wounds should be cut out including at least 2.5 cm. of the skin around and 5 mm. beneath the wound. They should be packed separately in rectified spirit, labelled and sent to the Forensic Science Laboratory.

If surgical wounds are made on a shotgun or stabbing victim, the surgeon should make adequate documentation of their location and nature in his records or on the hospital chart, so as to prevent confusion, if the patient dies and an autopsy is performed.

Track taken by the Bullet through the Body: Bullet tracks should be numbered and described individually. Probes should not be introduced through the track. The path taken by the bullet through the body should be carefully traced by dissection with the organs in situ.

It is useful to measure the height of both entrance and exit wounds from the under surface of the heel. This shows the direction of the track, and also the height above the ground at which the bullet entered and left the body, if the person was in standing position when struck. The bullet track should be described in relation to the planes of the body:

1. from front to back or from back to front,
2. from left to right or from right to left,
3. from above downwards (caudad), or from below upwards (cephalad).

Angular estimates, i.e., vertical, horizontal and sagittal planes of the body are also useful to complete the description. To release the bullet from the bone without actually handling it, the segment of bone containing the bullet should be excised, or sawed, followed by manual bending. Frequently, the track of the bullet is unpredictable due to its deflection by bone, and the bullet may be found in a most unexpected situation.

When a cavity has been penetrated and blood has collected, the bullet should be searched in the effused blood. A high velocity bullet is rarely deflected. To avoid prolonged search for the bullet in the body, X-ray examination should be done before autopsy. Rib borders or the border of other bones must be examined for roughening or fracture, which may explain the deflection of bullet, If there are multiple tracks, each should be followed from the point of entrance to termination. The track made by the bullet widens as it goes deeper.

If a bullet grazes a bone, it may produce a gutter with or without fracturing it. If a bullet passes through the bone, a track of tiny radio-opaque metallic particles removed from the surface of the bullet will be seen in X-ray. The size of pellets is difficult to measure after the shot is tired as it becomes deformed. All bullets and recognizable parts of bullets in the victim must be recovered, and described as to where it was found, whether it is intact, deformed or fragmented, whether the bullet is lead or jacketed, etc.

Next to bone, the skin offers the greatest resistance to the penetration of a bullet. A bullet passing through the body may come to rest just underneath the skin on the opposite side. The type of missile and the point of recovery should be noted. The location and character of exit wounds should be noted. All wadding in the body should be recovered to know gauge of the shotgun and the type of ammunition.

When a rapidly traveling object is slowed by passing from a thin to a dense medium, there is a release of kinetic energy which may be so violent as to fracture bones in the immediate vicinity of the track although the bones are not actually struck. Shock waves will also pass through the tissues causing injury remote from the actual wound. When a high velocity missile passes through soft tissue, it is followed by cavitation due to the released energy.

This primary cavity then collapses, and is followed by lesser secondary cavitation, which creates a negative pressure and debris is sucked into the track. When a high velocity missile strikes a relatively solid internal organ, such as the heart, this organ may disintegrate as if an explosive charge has been detonated in its substance.

Part of the energy of the bullet is spent by the tip to break the resistance of the tissues, and another part to push the tissues aside. This radial displacement producing transient cavitation is important with regard to the severity of tissue damage. If almost all the energy of the bullet is lost during penetration of the scalp, bone and dura, it passes through the brain without producing cavitation until it comes to rest. If the bullet passes through the brain with great velocity, the wound track expands immediately after the bullet has passed through.

This expansion develops in few microseconds, during which time brain is suddenly pressed against the inner table of the skull and other firm structures, and momentarily bulges out of entrance and exit wounds and collapses equally fast. The track of damage may be 4 to 5 times the diameter of the bullet, as seen by a track of hemorrhagic pulped brain tissue. Prior to cavitation of brain, skull fractures result. If the fractures extend beyond the area of entrance and exit and the cavitation is very severe, the skull may burst by the pressure of the brain.

A large portion of the brain may be thrown out of the bursting skull and found relatively intact. This is known as KRONLEIN SHOT. If such explosion does not occur but cavitation is severe, the sudden pressure on the tissues surrounding the wound track causes immediate necrosis due to shearing forces acting on submicroscopic structures of cells. A ring of tissue hemorrhage is found outside the necrotic tissue.

Contusions are also produced at a distance from the wound track due to displacement of portions of the brain due to the sudden space-occupying entrance of the bullet into the brain and by the associated cavitation. They occur independently of the location. Small caliber, low velocity bullets produce cavitation but fail to perforate the head on the opposite side. Sometimes, the entire track or one segment of it is found several times larger than the bullet. This occurs when the bullet passes sideways through the tissues or when it tumbles.

Bullets may be found in or on bodies either due to being fired from a gun or having been discharged from the cartridge as a result of heat-induced explosion. An exploded bullet does not show land.and-groove markings and the cartridge case is devoid of firingpin impression. Intense fire causes melting of ammunition and leaves a pool of molten lead which may stick to the body as tiny droplets. X.ray shows ‘birdshot’ pattern in films.

DESCRIPTION OF A FIREARM WOUND: There is a gunshot wound of entrance in the left anterior thoracic wall. This is just above and immediately medial to the left nipple and is situated 40 cm. below the top of the head and 10 cm. to the left of the midline. The wound is circular in shape, 0.8 cm. in diameter, and is made up of a 0.2 cm. radial dimensional abrasion ring concentrically placed about a 0.4 cm. diameter defect. There is no soot deposit or powder tattooing. A small amount of blood comes out from the defect upon manipulation of the body. A track is established from the gunshot wound of entrance on the left anterior thoracic wall, passes through the third interspace, through the lingua of the left lung, through seventh thoracic vertebra. Here, embedded in the bone, is recovered a full metal jacketed bullet of 0.25 calibre. This is marked ‘X’ and retained. A left haemothorax of 1200 ml. of tluid and clotted blood is present.

PRESERVATION, MARKING AND PACKING OF EXHIBITS : All bullets recovered from the body must be preserved with correct labelling of the relationship of each bullet to the corresponding wound. This is important in case of dacoity or rioting, to know which of the several weapons may have fired the fatal shot. It is important to state from which portion of the body, or from which internal organ it was removed. When more than one bullet or other foreign object has been removed from the body of a victim, or found in or about his clothing, each one should be labelled and placed in separate envelope. Care must be taken in removing a bullet from the body so that marks due to artefact, such as, scratches are not produced on the bullet. Such markings may make difficult subsequent identification of the bullet. It is preferable to remove the bullets with bare fingers. A forceps protected with rubber tubing may be used. The appearance of the bullet should be described accurately, e.g., intact, deformed, fragmented, lead or jacketed and the calibre if known. The bullet should be weighed, and if its base is not deformed, the diameter of the base should be measured. The recovered bullet should be dried and not washed, because washing removes the powder residue. In shotgun injury, the pathologist need not recover every pellet present. A few pellets should be recovered for the ballistic expert to determine the shot size and possibly type of ammunition.

(1) Firearms: Identifying initials should be scratched on to gun’s frame, receiver, or slide and on the gun barrel.

(2) Fired Cartridge Cases : The identification mark should be scratched on the inside of the open end. They may be wrapped in cotton and packed in cardboard boxes.

(3) Fired Bullets: The identification marks should be scratched on the base, or just above the rulings on the ogive but not on the end of the nose, for the nose may pick up trace evidence, e.g., the pattern of the weave of fabric through which it has passed. It is wrapped in cotton and packed in cardboard box. Each bullet should be packed separately.

(4) Pellets, Slugs, Wads, etc: They may be packed in cardboard box with cotton after drying and the container labelled.

(5) Clothes : The area of the powder tattooing should be preserved by fastening a cellophane paper over it, and packed in a box.

Atypical Entrance Wound

(a) For a few microseconds after the bullet leaves the muzzle (up to about 50 meters for a pistol or 150 meters for a rifle), there may be a “tail wobble’ or “tail wag”. This is partly responsible for the great tissue damage and the large atypical entrance wound at short range.

(b) The gyroscopic effect of the bullet diminishes as it reaches the end of its ugh, until it begins to wobble, and then to tumble. In wobble, yaw or tumble, the impact of the bullet may be sideways or even backwards with an irregular lateral motion, due to which an irregular lacerated wound is produced. A bullet traveling in an irregular fashion instead of traveling nose-on is called a YAWNING BULLET, and a bullet that rotates end-on-end during its motion is called a TUMBLING BULLET. The amount of tissue crush might be three times greater when the bullet yaws to 90°.

(c) The tattooing seen on the skin may be altered by the use of ‘silencers’. Muzzle-brakes and flash hiders may produce peculiar blackening and tattooing patterns by allowing gases to pass in specific direction. Bullets fired through a shortened barrel, may be deformed or squeezed.

(d) In revolvers, weapon defects, such as cylinder misalignment will cause deformities of the missile, with breaking off of the metal fragments from the bullet occurring when the misalignment is great. Lesser defects of this type may cause tumbling.

(E) RICOCHET BULLET : A ricochet bullet is one which before striking the object aimed at, strikes some intervening object first, and then after recocheting and rebounding (glancing) from these, hits the object. They are rare, as most bullets on striking a hard surface break up or penetrate the surface. The critical angle of impact for ricochet for hard surfaces varies from 10 to 30°. The bullet ricochets off at an angle smaller than the impact angle. The bullet may ricochet before or after striking the body and may produce a non-penetrating or a penetrating injury.

Ricocheting of a bullet may occur with inferior firearms and low velocity bullets. The bullet may be deformed and flattened before striking the skin. The degree of deformity varies depending on the texture of the bullet. This produces a large irregularly oval, triangular or cruciate entrance wound with irregular abraded margins. As the bullet loses gyrating movements, abrasion collar is absent. Burning, blackening and tattooing are also not seen.

Sometimes, a bullet may strike an object and tumble, and hit the body side on, producing an elongated wound of entrance like a keyhole. The path of a ricochet is completely unexpected. Particles of the substance against which the bullet is deflected or has struck, e.g., soil, fibers, paints, etc. may be found adhering to the bullet. The nose of the bullet may be found facing the entrance wound due to deflection in the body. When the velocity is lost, the bullet only produces an abrasion or contusion.

Sometimes, after passing through the brain, there is not enough energy left in the bullet to penetrate the skull. It may rebound (ricochet) from the inner table of the skull like a billiard ball, producing a second track. If it ricochets for a second time, a third wound track is produced. If the bullet enters the skull at an acute angle towards the inner table, it may move along the dura tearing the leptomeninges and blood vessels and produce a shallow wound track along the surface of the brain. The inner divergent course of the bullet may be combined with internal ricochet.

(f) The bullet may strike the surface producing a contusion and fall to the ground. This is seen with relatively soft non-jacketed bullet fired from a firearm that has an eroded or worn barrel; and also when the ammunition used is of smaller size than the barrel of the gun.

(g) Bullet Graze or Slap : If a bullet strikes skin at so acute an angle that it does not perforate the skin, a grazing or slap wound is produced. It usually appears as reddish-brown, elongated, elliptical or triangular furrow or abrasion. The underlying dermis may or may not be involved, but the adjacent intact skin may be ecchymosed.

(h) The bullet strikes the sternum at just the right angle and is deflected, so that it continues around the rib cage, between the bone and the skin. It may come out at the back of the body after causing only a superficial injury; or it may lodge between the skin and the backbone.

Bullets that strike in unusual location may cause injury and death, but the wound of entry may be difficult to locate, e.g., ear, nostril, mouth, axilla, vagina and rectum.

 Single entrance and multiple exits

 If the bullet splits up within the body and divides itself into 3 or 4 pieces, there will be only one entry hole, but several exits. The bullet striking a bone may break the bone into fragments, which act as secondary missiles producing multiple exits. Sometimes, the jacket of a bullet may separate from the inner part upon impact on bone. In such cases, the jacket and the core each produce separate tracks.

With the semi jacketed bullet, lead core usually exits, and the jacket remains in the body. Sometimes, a fragment of metal separates from the bullet during its passage through the skull. The separated fragment proceeds under the skin until it exits at a distance of 3 to 5 cm. or remains lodged between the skull and the skin. The major part of the bullet will enter the skull and may exit in a different position. In such a case, a single bullet will produce two exit wounds. In bullet wounds of the head, many lead fragments may be found scattered throughout the brain and on X-ray may closely resemble a shotgun injury.

Bullet Striking the Skull but not entering it

Bullets may graze or rub the top and sides of the cranium without entering it. In such cases, entry and exit wounds are found on the scalp about two to three cm. apart, while the skull between the two wounds shows an oval or elongated gutter-like depression (gutter wound; key-hole defect). When the bullet strikes the skull at an angle, it may rarely deviate from its path by impact on the bone, to produce a continuous wound track .under the skin without penetration of the skull. The track may proceed for considerable distance, the bullet following the curvature of the skull.

Multiple Wounds of Entrance and Exit from a Single Shot

A bullet may pass through an arm and the chest so that four wounds result. A bullet passing through the chest or abdomen and thigh and lower leg, produces six wounds. This occurs when the person is running or sitting in an unusual position. When the body surface is irregular, such as the breast or buttocks, several re-entries and exits can take place. In such cases, examination of clothing and detection of nitrites and nitrates and microscopic examination of the sections of the wound is useful. The features of re-entry wound resemble those of wounds caused by long range fire.

Entrance Wound is present but Bullet is not found in the Body

This occurs when

• the bullet entering the stomach may be vomited,
• entering the windpipe may be coughed up,
• entering the mouth may be spit out,
• entering the gastrointestinal tract may be passed out in the faeces, and
• when it is so deviated or turned on coming in contact with the bone, that it passes out by the same wound as it entered.

Unexplained Bullets in the Body Occasionally, more bullets are found than there are entrance wounds. This occurs, due to defect in the weapon, or due to faulty ammunition, or with loaded firearm unused for several years. When such a weapon is fired, the bullet may fail to come out from the muzzle. When it is fired again, the second bullet may go off carrying the lodged bullet with it, and both the bullets may enter the body through the same entrance wound.

This is called a tandem bullet or piggyback bullet (tandem=one behind the other). The bullets may separate within the body, or before they hit the target. The features caused by flame, smoke and gunpowder may be diminished or absent and the wound may appear as if caused by long-range fire. This is because the pushing force of the second bullet is directed backwards due to obstruction caused by first bullet impacted in the barrel.

Souvenir Bullets: If a bullet is present for a long time in the body, there will be no fresh bleeding in the surrounding area. A dense fibrous tissue capsule usually surrounds it. A small scar indicates the original entrance wound. Lead poisoning may occur due to absorption of lead from lead bullets remaining in a body. Synovial fluid is capable of dissolving lead.

Fatalities with Blank Cartridges

A blank cartridge is one containing primer, gunpowder and wadding, but without a bullet or pellets. It contains ultra fast burning powder that explodes rather than burns. Wounds can be caused from the gases or from the closing part in the end of the cartridge. Wadding or gunpowder may cause laceration and may produce death from shock by pressure on nerves or by damaging main vessels, when blank cartridge is discharged close to the body. Distant shots with blank cartridge are harmless.

Firearm going off by itself

The firearm can go off by itself without any one touching the trigger due to some defect in its mechanism. Country-made guns and old worn guns may discharge on being pushed or thrown, or by the butt being dropped against the ground.

Frangible Bullets

They are designed to fragment upon impact, often to the point of disintegration. They are made mostly by lead or iron. Recovery and matching with a test bullet is difficult. If bone is penetrated, they are usually recovered in an eroded state. They do not ricochet.

In some bullets, the component parts tend to separate on impact. Such bullets are partially jacketed at the base, with the tip remaining an uncovered lead core. The components separate on striking the body and create their own tracks.

Duplex or Tandem Cartridge

This is used in military rifles, and contains two bullets which enter the target at different points, separated by as much as 30 cm. The base of the forward bullet is notched, into which the second bullet fits closely. The base of the ‘follow’ bullet is not quite at right angle to its long axis, due to which there is a difference in line of movement of both the bullets.

Artefacts

Surgical alteration or suturing of gunshot wounds create problems. The evaluation of the wound, whether it was an entrance or an exit wound becomes difficult (Kennedy phenomenon).

Bullet Embolism

Bullets entering an artery embolise into the femoral and popliteal arteries. With less frequent venous embolism, bullets enter veins of the lower limb or heart.

Concealed Firearm Wounds

If the body is covered with blood, the blood clots may obscure the injury. A wound in the mouth, nostril, ear, eye, or in any of the body orifices, e.g. rectum or vagina may not be detected, if due care is not taken.

In contact wounds, the burning and tattooing is not much. The blast effects are also much less and the splitting of the clothes or tissues is the sinie as that with the revolvers. The entrance and exit wounds may be of the same size and shape, if the bullet passes through the body without touching the bone, but even when no resistant structure is touched, there may be explosive effects and severe lacerated exit wounds.

The entrance wound is usually smaller than the diameter of the bullet and looks like a wound made by forcing lead pencil into skin. The edges are depressed, may have micro tears 1 to 2 mm in length, radiating from the surface, and surrounded by a reddish zone which becomes brown on drying. Bruising of the deeper tissues around the track of the bullet is seen. If the bullet strikes at an angle, the skin may split or be turned up. If it strikes a bone, extensive shattering and comminution of bone takes place.

In such cases, the wound of exit is usually a lacerated hole, varying from about 2.5 cm. to the size of the palm of the hand. Frequently, several small holes will be found around the large exit caused by fragments of bone being driven out. Bullet fragmentation is much more common in rifle injuries than those due to handguns. In wounds of the head within 300 metres, the brain is frequently pulped and a great part of the cranium slashed into fragments.

A bullet leaving the muzzle of service rifle rotates or spins round its long axis at the rate of about 2,500 revolutions per second, and for the first 200 to 300 metres, the base of the projectile has also a circular motion round the axis of flight, gradually losing this motion and continuing to spin in the true axis. If a resistant body is struck within a range of 200 to 300 metres, the effect produced by the spin of the bullet together with the intense liberation of energy is similar to that of an explosion, the tissues themselves exploding, not the bullet.

This explains the shattering of bones such as pelvis, femur, skull, etc. It also explains the severe laceration seen even when a rifle bullet fired at short range passes through soft tissues only. At these ranges, the bullet commonly disintegrates, and causes effects which give the impression that more than one shot has been fired. Between 300 to 1,000 meters, the spin of the bullet becomes regular, and it passes easily through the tissues and cuts a clean hole through the bones. Beyond this, it behaves like a low-velocity bullet.

ALTERATION OF GUNSHOT WOUNDS: The appearance of a gunshot wound can be altered by the following conditions:

• Drying of margins of the wound opening.
• Decomposition of the body.
• Healing of the wound itself.
• Interference by emergency care personnel.
• Surgical operation.
• Interference by non-professional personnel at scene of death.
• Washing or cleaning of the wound after death.

X-ray Examination of Gunshot Wound Victims: It helps to

• locate the bullet or pellets,
• locate bullet fragments or jackets,
• show the track of the bullet. Internal ricochet within the skull may be demonstrated, which helps to determine the direction of the fire,
• determine the break up pattern of the bullet. This may also indicate the type of ammunition used,
• determine defects in bone,
• locate air embolism accompanying large vessel damage by the missile.

Entrance Wound (in-shot wounds)

They may be classified on the distance of the muzzle of a firearm from the body; contact shot, close shot, near shot and distant shot. The flame extends up to 8 cm; smoke up to 30 cm. and unburnt and partially burnt powder grains and small metallic particles up to 60 to 100 cm in case of rifle and 40 to 75 cm. with handguns.

The amounts of smoke, flame and powder grains and the distances to which they will be carried will vary depending upon the type of gun powder used, the amount of powder load, the size and weight of the projectile, the tightness of fit between the projectile and gun barrel and the type of firearm. Silencers will filter out a great proportion of soot and powder particles due to which the range appears greater than it actually was

Contact Shot: In firm or hard contact (muzzle pushed hard against the skin), the resulting wound is similar to that from a shotgun. In some contact wounds, the imprint of the muzzle of the gun is found as patterned abrasion on the skin around the wound. This results from the great distension of the subcutaneous tissues from the entry of gases which forces the surface against the muzzle. The mark may be an incomplete, indistinct bruise and occasionally a perfect imprint of the muzzle.

Many muzzle impressions are not recorded due to the rapid removal of the weapon by recoil. When a firearm is fired, the shooter gets a jerk on the shoulder or wrist due to recoil movement of firearm. The discharge from the muzzle, i.e. gases, flame, powder, smoke and metallic particles are blown into the track taken by the bullet through the body. The wound is large and triangular. stellate, cruciate or elliptic shows cavitation due to the expansion of the liberated gases in the skin and tissues, which show laceration. The margins are contused and everted due to gases coming out of the entering wound under pressure.

Singeing of the hair may be present due to the escape of hot gases by the sides of the muzzle end. The area immediately around the perforation is abraded, and this thin rim of abrasion is usually covered with powder residue. Tattooing begins when the muzzle to target distance exceeds one cm. In firm contact with the skin where the bone is not shallowly situated, the ever expanding gas continues to penetrate deeper, to be scattered in the soft tissues of the body. The wound is not eruptive or explosive in appearance.

In contact shot, the muzzle blast and the negative pressure in the barrel following discharge may suck blood, hair, fragments of tissues and cloth fibres several cm. back inside the barrel called “back spatter”. Back spatter is more common with shotgun. Sometimes, blood may soil the hand of the person firing the gun. In loose contact or near contact shot, some of the gases escape with the resulting scattering of the muzzle blast and an unusual arrangement of soot is seen on the skin known as corona.

The corona consists of a circular zone of soot deposit surrounding the bullet defect, but separated from it by a band of skin without a deposit of soot. This is due to the gas expanding about the muzzle, first at a velocity too high to allow for the settling out of soot, with a subsequent loss in velocity at a short distance from the muzzle, allowing the soot to finally deposit on the skin. Wound has clear margin, inverted, abraded and surrounded by soot. The blast effect is not as marked as in tight contact, and splitting of the wound edges does not occur.

Evidence of burning is noted on microscopic examination in the edges of the contact and near- contact bullet wounds due to the flame of muzzle blast. Singeing of the hair may also be seen. The discharge from the muzzle, i.e., gases, flame, powder, smoke, and metallic particles are blown into the track taken by the bullet (projectile or missile) through the body. The powder residue is usually grossly visible in the subcutaneous and deeper areas. The entrance track is blackened by powder and smoke and seared and charred by flame. In loose contact gas and soot escape from the side of the barrel, causing an eccentric area of burning and blackening.

Head wounds appear, as very large explosive type of injury with bursting fractures. The skin wound is large and irregular because of the expansion of gases between the scalp and the skull which causes eversion and splitting of the skin at the margins of the entrance wound. This results in undermined, ragged, stellate, triradiate or cruciform opening with everted margins from which tears radiate. The tearing may be severe, as the gas raises a large dome under the skin which then ruptures.

Such wounds are usually produced by large calibered pistols. A subcutaneous pocket containing blood mixed with gunpowder is formed by separation of the tissues. When a small calibered pistol is used, the wound may be small and regular. Soot may be deposited on the bone surrounding the bullet hole. This should not be mistaken for lead rubbed off on the bone during the passage of the bullet, which is seen only in a localised area.

Frequently, soot passes deeper into the wound track and a faint gray or black discolouration may be seen on the inner surfaces of the skull around the bullet hole and on the dura mater. Fissured fractures often radiate from the circular defect due to the considerable sudden expansion resulting from the muzzle blast. Fractures of the orbital roofs occur due to the same mechanism, but the dura over the orbits is usually not damaged.

A bullet travelling the cranial cavity destroys the structures in its pathway and produces an expansile or explosive effect. A bullet fired from a short distance may produce an explosive effect sufficient to burst the scalp, shatter the skull and dislodge the brain. In less severe type of injury, a cone of damaged cerebral tissue is seen surrounding the wound track. When a bullet moves through the body, it transfers kinetic energy to the surrounding tissue, which is thrown forcefully away from the bullets path in a radial manner, and a temporary cavity is formed in its path. The margins of the wound of entry, subcutaneous tissues and muscles around the track of the bullet may be bright pink due to the presence of CO. Abdominal wounds show cavitation because of the blast effect.

When the part is clothed, the bullet hole in the cloth touching the muzzle is sometimes surrounded by a flat ring corresponding to the outline of the muzzle. The loose fibres of the cloth in the centre of the bullet hole are often turned outward due to the expanding gases returning through the defect. These fibres are usually blackened by smoke. In synthetic fabrics, melting of the ends of these fibres may be observed sometimes.

Varying amounts of soot is deposited on the edges of the bullet hole. If the clothes are bloodstained, deposits of soot may not be recognised, but the inside of the garment may show large deposit of smoke. This is due to the spreading of smoke by the muzzle blast between the skin and the clothing and is seen commonly if the shot passes through several layers of material.

Each layer is blackened on both sides of the fabric, but the skin wound does not show blackening or tattooing. If there is no intervening clothing, the smoke passes into the wound but a small amount is deposited on the wound edges, especially if contact with the muzzle was loose. Fine granules of powder and deposits of soot can be demonstrated in the depth of the wound by a layerwise dissection of the injury.

Close Shot: This term is applied when the victim is within the range of the flame, i.e., 5 to 8 cm. The term ‘point blank’ is used when the range is very close to or in contact with the surface of the skin. The entrance wound is circular with inverted edges, but the rebounding gases may level up or even evert the margins. The skin is burnt with singeing of the hair. The skin surrounding the wound is hyperaemic and shows some bruising, burning, blackening and tattooing. The palms and soles are very resistant to powder tattooing.

The blackening can be wiped off the skin by a wet cloth, but the tattooing cannot be wiped off. Carboxyhaemoglobin will be present in the wound track in diminishing concentrations up to 30 cm. The length of the barrel of a firearm has considerable effect on the spread of smoke produced on the target, e.g., a gun with a 5 cm. barrel will spread the smoke over a much larger area than a weapon having a 15 cm. barrel, fired from the same distance and using the same type of ammunition.

Usually, as the distance between the muzzle and the target increases, the pattern of soot or powder on the target increase in diameter and the density of particle deposition decreases. In handguns, up to 15 cm. from the muzzle, abundant gunpowder and diminishing amount of soot are deposited on the target. Hair in the surrounding area may be clubbed, swollen at intervals by heat, or burnt. Abraded collar and grease or dirt collar are present. Between 30 cm. to one metre there is no burning and blackening, but some amount of tattooing is usually seen. The internal injuries are almost same as in the case of contact shot.

Near Shot: This term is applied when the victim is within the range of powder deposition, and outside the range of flame, i.e., up to 90 cm. If the discharge occurs at a distance of about 15 cm., the lacerating and burning effects of gases are usually lost due to the dispersion cooling of the gases before they reach the skin. The entrance wound is seen as a round hole, slightly smaller than the diameter of the bullet, due to elasticity of the skin, with a bruised and inverted margin and a zone of blackening and tattooing.

The individual tattoos are caused by the individual unburned powder grains being blown into skin. A small magenta- coloured zone, an actual micro-contusion is seen surrounding each tattoo point, which is caused by the trauma of the high speed impaction of the powder grain with rupture of small blood vessels and resulting minute haemorrhage. If the bullet strikes the body at an angle, blackening has a pear- shaped area, with the larger area on the side nearer the barrel.

As the distance increases, the intensity decreases and blackening and tattooing is spread out over a large area, and there is no singeing of the skin. Abrasion and grease collar are present. Occasionally, when the range of fire is short, small fragments of metal derived from the interior of the barrel of the gun or the bullet itself, are embedded in the skin in the vicinity of the entrance wound.

Distant Shot (Above one metre) The entrance wound is smaller than the missile due to the elasticity of the skin, circular, and margins are inverted. Distant entrance wounds of the palms and soles are irregular, often having a stellate appearance, without an abrasion ring, and look like exit wounds. Burning, blackening and tattooing are not seen. The skin adjacent to the hole shows two zones, the inner of grease collar and the outer of abraded collar.

In case of semi-jacketed bullet, the jacket separates as it goes through the body, and the core mushrooms into small pieces. X-ray gives a picture of “lead snowstorm”. If a semi-jacketed bullet passes through an intermediary target, the jacket may separate from the core, and both missiles may penetrate the body. When a bullet passes through an intermediary target, such as glass, may cause superficial lacerations around the entry wound and these are referred to as pseudo-tattooing, which are larger and more irregular than that caused by powder. The calibre of a bullet cannot be determined, if it strikes the skin surface obliquely.

Stretching and cavitation and dissipation of kinetic energy are the major causes of the lethal effects of a bullet, together with deformation and fragmentation.

The Abrasion Collar (marginal abrasion): As the bullet strikes the skin, it first indents and then stretches the skin surface, so that perforation takes place through a tense area. After the bullet has perforated the skin, the elasticity of the skin causes the skin defect to contract. The skin is abraded (abrasion collar) around the hole due to rubbing of the gyrating body of the bullet against the inverted epidermis and heat of the bullet.

A black coloured ring “grease or dirt collar” (bullet wipe soiling) is seen as a narrow ring of skin, lining the defect, and is sharply outlined. This is caused from the removal of substances from the bullet as it passes through the skin, i.e., bullet lubrication, gun oil from the interior of the barrel, lead from the surface of the bullet, barrel debris, etc. It is more marked in a distant shot. Infrared photography clearly indicates the presence of black ring around the bullet hole.

Dirt collar is less common if the bullet is jacketed. By contrast, soot is dark in the centre and fades towards the periphery. The abrasion collar surrounds the dirt collar. The abraded collar is reddish at first, but becomes reddish brown as it dries. Some contusion is present in abraded collar, and as such, it is also called “contusion collar”. These two features are proof of an entrance wound. Irregular and occasionally patterned abrasion collar is sometimes produced by coarse article of clothing scraping on the skin.

Abrasion collar may be absent when the tissues are soft and yielding, e.g. in the abdomen or buttocks. It may also be absent, especially where skin is taut, and in some high velocity wounds. In addition to abrasion collar, there is often a slightly wide circle of peeled keratin, where the stratum cornem of the skin is raised to form a slightly frayed edge around the entry wound.

Skull : In the skull, the wound of entrance shows a punched-in (clean) hole in the outer table. The inner table is unsupported and a cone-shaped piece of bone is detached forming a crater that is larger than the hole on the outer table, and shows beveling (sloping surface). Fissured fractures often radiate from the defect.

As the bone fragments have to pass through the dura before entering the brain, lacerations are usually irregular and involve leptomeninges. Pieces of bone from wound of entrance are often driven into the cranial cavity and may establish the bullet track. Pieces of bone may produce short accessory wound tracks. At the point of exit, a punched-out opening is produced in the inner table and beveled opening on the outer table.

Beveling is produced when the unsupported diploe everts and fragments on the side where the bullet leaves, this in contrast to the approach side where the rim of the defect is supported by the underlying bone. The exit wound is larger due to the deformity and tumbling of the bullet after entering the skull. There are often fissured, sometimes comminuted fractures radiating from the central hole. Asymmetry of the beveling is useful in assessing the angle of fire.

The same appearance is seen in sternum, pelvis, ribs, dentures and thumbnails.

Puppe’s Rule: It can determine the sequence of shots, when several bullets have struck the cranium. This rule is applicable to any multiple blunt force, causing skull fractures. This rule has been developed by Madea in relation to bullet injuries. The test depends on the observations of the fracture lines either when they intersect each other, or when they intersect a cratered lesion, so that one can determine which crack or defect must have been formed first.

Direction: If the bullet strikes the body at right angle, the abrasion collar is circular and uniform because the scraping by the bullet is equal on all sides of the wound. If the bullet strikes the body at an angle, the wound itself is round, but the marginal abrasion is oval or elliptical, due to increased width on the side from which the bullet comes, due to the bullet moving across a wider surface of the skin on that side.

The direction of the bullet is from the wide to the narrow side. Oblique angle will cause an elliptical mark, the length of which increases as the angle decreases. When the bullet enters the body from an oblique angle, one edge of the wound is shelved or undercut, which indicates the direction from which the bullet entered. Shelving is usually seen in the deeper layers of the skin rather than in the tissues below.

THE WOUNDING POWER OF BULLETS

The size and velocity of the bullet are the two most important factors. The wounding power of a bullet is proportional to its mass, multiplied by the square of its velocity. Another factor is the density of the tissue, e.g., destruction is greater in dense tissue such as bone than in soft tissues. The tissues show considerable damage due to the wobbling of a bullet within the body.

A bullet travelling at high velocity produces a clean, circular punched-out aperture or slit and usually perforates the body. It is not deviated from its path by striking a bone, but may cause its comminution or splintering. A bullet of low velocity causes contusion and laceration of the margins. It is easily deviated and deformed by striking some hard object, and often lodges in the body. Large bullets cause greater damage than small ones. Round bullets produce larger wounds than conical ones. A bullet of smaller size than the calibre of the weapon may cause only bruising.

Clothes: If the shot is through a clothed surface, examination of clothing only can indicate its range. In a contact shot, the clothing usually shows a cross-shaped perforation, and the skin around the bullet hole and the deeper layers of the cloth are blackened. In close shots, the clothing may absorb or filter out all of the products of discharge except the bullet. An entrance hole in clothing, if made by a lead or full metal-jacketed bullet, may produce a grey to black rim known as “bullet wipe” (grease, soot or debris from the barrel of the gun). Sometimes, pieces of cloth are carried into the wound of entrance.

Exit Wounds

If the bullet fragments on impact, an exit wound may not occur. The bullet may be reduced to granules, and there may be difficulty to remove them from the body, even when identified by X-ray. Full metal-jacketed bullets usually exit undeformed. Exit wounds may vary considerably in size and shape. They may be round, stellate, cruciate, elliptical, crescent-shaped. An exit wound produced by a tumbling bullet or a bullet passing sideways through the tissues may be elongated or slit-like resembling a stab, incised or lacerated wound.

The same appearance may be seen in a part of the body in which the skin folds or changes direction, e.g. in the buttock crease, under the arm, or in the groin or umbilical area. Exit wounds of the head are usually star-shaped resembling contact entrance wounds. In some cases, the entrance and exit wounds may look alike. The exit wound is of help in determining:

• the direction of fire,
• posture of the victim at the time of the shooting, and
• the number of bullets in the body.

When the weapon has been fired in contact with the bone or at very close range, the exit wound is usually smaller than the wound of entrance. With increased range, the exit wound is larger than the wound of entrance. With high velocity bullet, the two wounds may be of the same size. The edges of the exit wound may be puckered or torn and everted and pieces of contused, haemorrhagic subcutaneous fat may protrude through the defect. The edges are free from signs of burning, blackening or tattooing and there is no contusion or abrasion collar.

If the skin at the exit wound is firmly supported, the exit wound appears as a circular or nearly circular defect surrounded by a margin of abrasion (usually broader than that of entry wound), resembling a wound of entrance (shored or supported exit wound). The shored type of exit wound caused by a bullet fired at long range or through clothing, or when the firearm is of small calibre and discharged in contact with the skin at a point where bone is not immediately below the skin surface, resembles wound of entry.

Many shored exit wounds are caused if a firm object, e.g., a belt, the waist band of trousers, etc., brassiere, collar and tie, is pressed against the body at the site of exit wound, or if the body is leaning against a hard surface such as a wall, back of a chair or the floor, door, car seat, mattress, bedding, or if the person was lying down. In such cases the skin, crushed by the exiting bullet, produces an irregular, lopsided and large abrasion around or adjacent to the wound (shored’ exit wound).

In a fatty person, the edges of both the wounds of entrance and exit may be everted due to protrusion of fat. They may also be everted in decomposed bodies. The variation in the shape and large size of exit wound are due to:

• The bullet tumbles in the body and fails to exit nose-end first.
• The bullet is deformed.
• The bullet breaks up in the tissues and exits as several pieces.
• Fragments of the bone may be blown out of the body with the bullet.
• The unsupported skin at the exit tends to tear and break into pieces.

Rarely, slit-like exit wounds are seen probably due to the deformity of the bullet, caused by impact of the bullet on bone during its passage through the body. Such wounds are mostly seen on the head and over the shoulders. Occasionally, a bullet may be found protruding from an exit wound. In incomplete exit wound, bullet lacerates the skin but is trapped and lodged within skin wound.

Entry wound may be larger than exit due to:

• tearing of soft tissues by in rushing gases,
• tumbling or yawning of bullet,
• breaking of bullet with only a portion of it exiting,
• tangential entry with focal avulsion of tissues,
• bullet entering through folded or creased skin.

Revolvers and automatic pistols cause similar wounds, but penetrating power of bullets of pistols is much greater because of the greater velocity and because of their being coated with hard metal.

Contact and near contact shotgun wounds

They are single, usually round, equal to the bore in size, often ragged because of individual shot and tearing due to gases. In tight contact wound, soiling and burning are minimal or absent. The margins of the skin perforation are charred by flame, and the abraded border is usually soiled with powder residue. Usually smoke soiling of at least some of the margin of the wound is seen. As the gases are blasted within the wounds, the subcutaneous and deeper tissues show severe disruption. The rapid entry of gases causes a momentary vacuum intermediately below the skin, which may cause extrusion of the soft tissues, e.g., fat through the wound.

Particles of unburnt powder are driven to some distance through the wound and some of them are found embedded in the wound. These particles cause hemorrhage in deeper tissues and form aggregates of hemorrhage in the margins of the wound. Thus, the margins of the wound will be contused. If the contact is tight, muzzle impression (copy or recoil abrasion) is seen due to firm mechanical pressure of impact of the metal rim against the skin, and also due to the subcutaneous expansion of gases lifting the skin forcibly up against the muzzle. The muzzle imprint may be an incomplete, indistinct bruise or rarely may be a perfect imprint of the end of the weapon.

Bruising can occur around the muzzle imprint. Muzzle imprint may be lost within the explosive damage associated with the discharge. But, in a double- barreled shotgun the unused barrel often leaves a characteristic patterned abrasion. In many cases, muzzle impression is not produced due to rapid removal of the weapon by recoil. In contact shot, the muzzle blast and the negative pressure in the barrel following discharge may suck blood, hair, fragments of tissues and cloth fibres several cm back inside the barrel called “back spatter”.

If the muzzle is not pressed firmly, and also due to the recoil of the gun, flame, gas and soot escape sideways and cause singeing and blackening of the surrounding skin. Corona may be present. CO in the gases combines with hemoglobin due to which the wound of entry and the wound track appear pink. This decreases gradually, but may be seen very rarely at an exit wound. Burning, blackening and tattooing of the tissue also take place in the depths of the wound. The outer shots are deformed by their passage through the bore and choke.

Cruciate, stellate or ragged lacerations are seen especially if there is a thick bone immediately under the skin, such as skull due to the extreme force of the blow back phenomenon, as gases expand beneath the skin and lacerate the margins of the wound, as they exit through the original entry wound. Contact wounds on the head produce greater disruption of the margins, and often show subsidiary linear tears in the skin extending from the margins of the main wound.

A large irregular hole is produced in the skull, with fissured fractures running from its margins. The bone may show burning and gunpowder blackening in the margins. The entire contour of the face and head may be destroyed, and the actual point of the muzzle impact of entry wound may be difficult to locate. Extreme mutilation is caused due to the explosive effect, because the gases have restricted space for expansion.

Comminution of the vault of the skull is usually accompanied by extensive fissured fractures, or ‘crazy paving’ fracture, of the base of the skull, and the roofs of the orbits, and middle ears. A large exit wound may be produced with disruption of the cranium and projection of brain tissue for some distance. An eye may be blown out of its socket (burst head). An entrance wound in the mouth or nose may or may not be accompanied by an exit wound. Resistance by the hard palate reduces the power of the shot, and the shot lie mostly in the space between the skull and scalp, at the back or side of the head.

Abrasions or bruising of one or both lips with or without laceration is seen. Splitting of the angle of mouth may occur due to blast. In the neck region a large exit wound or complete destruction may occur. In contact or near contact wounds on the abdomen, coils of small intestine may lie outside the abdomen due to entry of gas into the pentoneal cavity. On the chest, the skin and subcutaneous tissues may be peeled away from the rib cage to form a pocket which then collapses.

If the part is clothed, smoke will escape sideways and may be found in each layer of clothing and on the skin. The cloth may be singed at the edge of the hole, and there may be a ring of burning around the skin wound.

Close Range (up to 1 metre)

In loose contact with skin, the blast effect is less as compared to tight contact, and splitting of the wound margins usually does not occur. Within a distance of about 30 cm., tissues surrounding the wound are singed by flame, and blackened by smoke, and tattooed by unburnt or partially burnt powder granules. If the powder is smokeless, there may be greyish or white deposit on the skin round the wound. The deposit of smoke is known as smudging, fouling or blackening. This spreads more widely than powder tattooing.

The blackening can be removed by a wet cloth. Unburnt particles of the powder are embedded in the skin producing tattooing (stippling or peppering). The particles sticking to the epidermis or lodging in the epidermis superficially can be removed with pressure wiping, showing punctuate wounds. The hairs of the trunk and limbs may be completely burnt around the wound. If the distance is greater, the keratin of the hair may melt with the flame, and then solidify on cooling, producing clubbed appearance of the hairs because of rounded bulges at the tips.

Soot soiling diminishes as the distance increases. There may be a wide flare or narrow rim of hyperaemia or even blistering from the flame. If the gun is fired at right angle to the body, the burnt area is circular, and if fired at an angle it is oval, the direction of the firing being indicated by the nearness of the wound to one or other end of burnt area. The end nearer the wound is the direction towards which the shot traveled.

Primer residues are easily removed from the skin by wiping, rubbing or washing. The use of silencers to muffle the sound of discharge reduce the amount of smoke and powder significantly and cause misinterpretation of the distance from which gun was fired. The burnt area darkens and parchments on drying after death. Blackening and tattooing can be readily demonstrated by infrared photography on both skin and clothing. As range becomes greater, the intensity of blackening and tattooing decrease and the spread increases in a fairly regular manner.

The tissues up to 30 cm. along the track, and around the wound may be cherry-red due to absorption of CO. The wound is single, circular or oval, similar to contact wounds, though the blackening and tattooing are more extensive. The margins of the skin wound may be clean-cut or slightly ragged. There may be annular bruising around the wound due to tissue damage from the entry of gases.

Felt, wads or plastic cups from the cartridge will be found in the depths of the wound. The deeper tissues show marked disruption. Carbon monoxide may be present in the blood absorbed from the damaged tissues. In some cartridges, plastic granules may be used as a filler between the lead pellets, and this colored material may be found within the wound or on the skin up to 2 to 3 meters and produces very fine, punctuate abrasions around the pellet holes. The plastic cup type wad opens up between 30 to 60 cm. so that four petals stick out, and a circular entrance wound is produced with a Maltese cross pattern of abrasion encircling it. By 90 cm. air resistance folds back the petals and a single hole of entrance will be produced.

At a distance of 60 to 90 cm., small shot produce a single circular aperture, 2.5 to 4 cm. in diameter, with irregular and lacerated edges. There is no burning or blackening. Some amount of tattooing is usually seen. The tissues within and around the wound are not cherry-red. Between 30 cm to one meter, the rim of the wound is irregular and shows some scalloping, often referred to as a “rat -hole” The shots are scattered after entering the body and cause much damage to the internal tissues.

In the skull, there is less disruption than that at contact range; bursting open of the skull and scattering of its contents is not seen. The column of pellets has a cutting action which produce a clean hole. Shotgun wounds at contact and close range cause much more destruction of tissues than rifled weapons, due to the greater amount of gas produced, because of larger amount of gunpowder.

Short range (1 to 2 metres)

A single circular aperture 4 to 5 cm. in diameter, with irregular and lacerated edges is produced. There is no burning, blackening or tattooing. Between one and two meters, the shot mass enters the body in one mass, producing a round hole, four to five cm. in diameter for all gauges and all chokes. Wads may be found deep inside the wound up to two meters. Annular or linear abrasions are caused by the impact of the clothing against the stretched skin during the penetration of the shot en masse.

Intermediate Range (2 to 4 metres)

The minimal distance at which shot mass begins to spread is extremely variable. It may be one meter with sawed-off shotgun but is usually about two meters with cylinder bore guns and four meters with full choke guns. At a distance of two meters, the shot mass begins to spread and individual pellet holes may be detected, which are usually round and show a rim of abrasion at their margins. The wound of entry is irregular. Beyond two meters the wads often strike the body below the shotgun wound. It may penetrate the skin or it may only bruise the skin. The wads found within the wounds are useful to determine bore of the gun.

At a distance of three meters, the central aperture is surrounded by separate openings in an area of about 8 to 10 cm. in diameter. As muzzle-target distance increases, the main entrance defect progressively becomes smaller, and individual pellet wounds increase in number. Occasionally, several individual pellet entrance wounds are in contact producing scalloped defects which are larger than the individual pellet holes. As lead is soft, pellets deform easily due to friction as they rub against the inside of the bane!. The heat can cause melting and fusion of pellets.

Long or Distant range (above 4 metres)

Distant wounds are those in which all shots penetrate separately. At a distance of 4 meters, the shots spread widely and enter the body as individual pellets producing separate openings in an area of 10 to 15 cm. in diameter. Each individual pellet reproduces its own track.

In the skull, the energy of the shots is greatly reduced perforating the skin and bone, so that they usually do not travel the entire brain substance. Cavitation is usually minimal or does not occur, and distant contusions are rare. Laceration of blood vessels by pellets or bone fragments may produce infarcts. In shotgun discharge, there is no temporary cavitation. The spread of pellets from a fully choked barrel is:

10 metres . . . 25 cm.

15 metres . . . 35 cm.

20 metres . . . 45 cm.

30 metres . . . 75 cm.

The spread is almost double from an unchoked barrel. At about 30 meters, the pellets only penetrate the skin or muscle. Death beyond a range of 30 meters is rare. It is possible for a single pellet or shot to cause death. The diameter of the wound is measured from the outermost of the individual pellet holes in centimeters. For cylindrical barrels one-third of the spread of shot in cm. equals the range in meters.

The spread for fully choked barrels is about half that of a cylindrical barrel. The estimation of range is difficult when replaceable or variable extensions called ‘chokes are used at the end of the muzzle of shotguns. Some chokes and even the barrels themselves are replaceable. Passage of shotgun pellets through any target before they strike the body, cause the pellets to spread, e.g., window glass. screen, or layers of clothing.

COUNTRY-MADE FIREARMS

The injuries caused to the victim vary considerably depending upon the nature of projectiles. Metal scraps may produce small incised or incised-looking wounds; punctured wounds may be produced by nails, and lacerations and contusions by stone pieces. The distance up to which the smoke, flame and carbon particles travel is approximately half of that from factory made firearms. The pellets begin to disperse at a distance of 30 to 45 cm.

The muzzle velocity is low and the barrel can accommodate a sub-caliber projectile or cartridge. As the characters of the firearms and components of the cartridge vary widely in country-made firearms, the data applicable to factory-made firearms to calculate the distance of firing cannot be applied. For estimating the distance of firing, the only ideal method is to carry out test firing with the suspected weapon.

BILLIARD BALL RICHOCHET EFFECT

At close range, while the shots are bunched, they strike one another upon impact on primary target, i.e., the skin or clothes, and spread out in a wide pattern as they pass through the body. This causes the shots to spread widely and may suggest a greater range of fire than actually occurred. Similar spread is seen if the shots strike any other intermediary object, e.g., door or window, before reaching the victim. The phenomenon is termed the billiard ball ricochet effect. The final shot spread as seen in X-ray gives a true picture of the range of fire, only when the range of fire is great enough that the shots are spread out, before striking the target.

In decomposed and burned bodies where the skin pattern cannot be seen, the range of fire can be determined by X-rays.

BALLING OR WELDING OF SHOT

Balling of shotgun pellets results in the conversion of shot into a compact mass, which can travel for few meters in this form. In such cases, a circular or oval entrance wound of about 5 to 10 mm in diameter, and widespread, small, circular punctures are seen. suggesting the use of two different weapons, one a shotgun at distant range and the other a rifle.

This can be due to faulty manufacture or old ammunition, but this is rare. It can be due to hand-loading of cartridges, if too much powder is used, if wads of incorrect kind are inserted, or sealing pressure on the wads is too high. The most likely cause is due to pouring of paraffin wax into the cartridge after removing the outer cardboard or by replacing some of the pellets by a large ball-bearing which is held in place with wax.

The Size of the Shot: The smaller the shot, the more minutely irregular are the edges. The penetrating power of the large shot is greater than that of the smaller shot. At close range, the wounds produced by shot of various sizes are similar, but small shots usually lodge in the body.

 The Nature of the Explosive: With smokeless powder, blackening and tattooing is less marked at all ranges than with black powder.

The Gun itself: The pattern of wound depends on the length of the barrel, the bore, absence or degree of the choke present. Shorter barrels usually produce greater deposits over larger areas.

Irregular missiles, such as pieces of stone, iron, beads of metal, seeds, etc., used in muzzle-loading guns, produce several irregular lacerated wounds, and the exit wounds are larger than the entrance wounds. Death from shotgun injury is usually due to hemorrhage.

The direction of the fire may be determined from the passage of individual shots through the clothes and tissues, from the grouping of shot marks and the direction of glancing shots.

Exit Wounds: Usually shotgun pellets do not exit from the body except:

• Contact wounds.
• Tangential wounds where some of the pellets have a very short track through the body.
• Thin part of the body, such as the neck or extremities.
• Wounds caused by large caliber buckshot or rifled slugs.

At contact or near range, greater disruption of tissues occur than is seen in entrance wound. The margins are everted as the unsupported skin is struck from within, the tissues tend to burst outward, and the skin fragments, but there is no singeing, blackening or tattooing of the margins.

There may be small, separate wounds made by individual pellets that have become separated from the mass. If the skin at the exit of a bullet is well supported, either by belt, corset, etc. or is pressed against a firm surface, e.g., wall, wooden or plaster board, etc. the skin surface will be rigid because of the pressure of the external substance, and the exit wound has clean margins.

SUICIDE : Suicidal stab wounds are found over accessible areas of the body. The common site is the chest over the heart region. The direction of the wound is upwards, backwards and to the right. The depth is variable, some are superficial and others enter the pericardium or heart. The suicide may not withdraw the point of the weapon from the skin, and stab himself repeatedly in different directions through the same skin wound. Rarely one stroke is fatal, and the knife may be found sticking in the wound.

In many cases, even multiple stabs do not cause death and the person may resort to other methods which present a puziling picture. To produce impalement on to a knife, there should be enough momentum by the victim moving toward the knife and it would need to be fixed firmly in some way. Stab wounds of the head are rare.

Usually, a number of stabs extending only to the bone are seen in the temporal region. Suicidal stab wounds of the spine, abdomen, neck and extremities are rare. Wounds found on a part of the body usually covered by clothes without corresponding cuts or rents on them are suicidal, as a person who commits suicide exposes his body by opening his clothes and then inflicts wounds. In some suicides, the victim may be able to conceal the weapon.

Common methods of suicide are: poisoning, hanging, burning, drowning, jumping from a height, stabbing and cutting and railway injuries.

HARA-KIRI: It is an unusual type of suicide, in which the victim inflicts a single large wound on the abdomen with a short sword while in a sitting position or falls forward upon a ceremonial sword and pulls out intestines. The sudden evisceration of the internal organs causes a sudden decrease of intra-abdominal pressure and cardiac return, producing sudden cardiac collapse.

HOMICIDE: Most deaths from stab wounds are homicidal, especially if found in an inaccessible area. The wounds are multiple, widely scattered and deeply penetrating, involving the chest and abdomen. lii case of a sudden surprise attack, a single wound is found at a vital spot. If there is a struggle, there may be a number of wounds, sometimes associated with defence cuts on the hands.

In a few cases, a number of wounds may be found in a localised area, almost of the same depth. These occur when the assailant threatens the victim, who is held by another assailant. These wounds are usually seen on the face or neck, and may be far away from the fatal injury. Homicidal stab wounds of the chest may have any direction, but the common direction is at an angle from left to right and from above downwards.

Fatal stab wounds of right chest usually injure right ventricle, aorta or right atrium. Stab wounds of the left chest usually involve the right ventricle when parasternal, and left ventricle as the stab wounds become more lateral and inferior. Severing of the left anterior descending coronary artery is rapidly fatal.

Most stab wounds of the heart and lungs occur over the front of the chest, rarely the sides, and least on the back. Stab wounds of the lower chest can injure the heart and lungs and also abdominal viscera. Rarely a single stab may produce multiple skin wounds, such as tangential stab of the arm may pass through superficial tissues and then enter the chest wall, or stab through a sagging female breast can pass through the edge and re.enter the thorax.

In OVERKILL HOMICIDE, assailant continues stabbing beyond the victim’s death. When a knife is thrown at a person, the skin resistance will cause significant loss of its kinetic energy and the stab may not be deep because of further resistance of the internal tissues. Postmortem stab wounds do not show bruising and are often yellow, or tan, due to absence of tissue perfusion, parchmented and sharply defined.

ACCIDENT : Accidental wounds are rare. They are caused by falling against projecting sharp objects like glass, nails, etc., or a person may be gored by the horns of a bull, buffalo, etc. An upward or downward track is quite inconsistent with an accidental stab wound. Impaling injuries are very rare and caused when a person falls or jumps from a building and lands on a fence or ornamental railings at play or mechanical catastrophe at work.

Accidental stab wounds occur if a person is impaled after an accidental fall on to a sharp-pointed object, or by a moving sharp object striking the person. In accidental stabbing, the weapon should be anchored or held firmly.

ACCIDENTAL, SELF-INFLICTED OR INFLICTED BY OTHERS: The following factors are helpful to determine whether the wounds are suicidal, accidental or homicidal.

• The nature, direction, extent and situation of the wounds.
• The presence of foreign matter in the wound or adherent to the margins.
• The nature of the suspected weapon or instrument.
• Scene of the crime.

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They are called penetrating stab wound, when they enter a cavity of body. When the weapon enters the body on one side and comes out from the other side, perforating wounds or through-and-through puncture wounds are produced. The wound of entry is larger with inverted edges, and the wound of exit is smaller with everted edges, due to tapering of blade. The victim of a fatal penetrating injury may not show signs and symptoms of injury until many hours have passed.

Characters of stab wound:

Margins: The edges of the wound are clean-cut. There is usually no abrasion or bruising of the margins, but in full penetration of the blade, abrasion and bruising (hilt mark) may be produced by the hilt-guard (metal piece between the blade and handle) striking the skin. The margins may be abraded and ragged if the cutting edge is blunt. The mark will be symmetrical, if the knife strikes the skin at right angle. if the knife strikes in a downward angle, the mark will be prominent above the stab wound, and if the knife strikes in an upward angle, the abrasion will be below the stab wound. In oblique stab wounds, a knife striking from the right will have an abrasion on the right side and vice versa. In such cases, the suspected knife should be examined to determine the compatibility of the shape of the abrasion around the stab wound, with the handle of the knife in question.

Length : The length of the wound is slightly less than the width of the weapon up to which it has been driven in, because of stretching of the skin. For measuring the length of stab wound, the edges of the wound should be brought together. Deliberate lateral, forward, or backward movement of the weapon during its withdrawal from the body tends to widen the wound, and the length will be more than the maximum width of the blade. If the instrument is thrust in, and is then completely withdrawn with the cutting edge dragging against one end, the wound would be extended superficially, producing a tail.

Width: By examining multiple stab wound in the body, the length and width of the knife blade can be determined approximately. The maximum possible width of the knife blade can be approximately determined if the edges of a gaping wound are brought together. Elasticity or laxness of the skin can change the width by one to two millimetres. A stab wound inflicted when the skin is stretched will be long and thin, which becomes shorter and broader when the skin is relaxed. The opening may be enlarged by backward, forward or a lateral movement of the weapon.

Depth : The depth (length of track) is greater than the width and length of the external injury. It is not safe to find out the depth of a stab wound by introducing a probe, because it may disturb a loose clot and may lead to fatal haemorrhage, or cause serious damage and may produce multiple false wound tracks. The depth of a stab wound is usually equal to, or less than the length of the blade that was used in producing it, but on yielding surfaces like the anterior abdominal wall, the depth of the wound may be greater, because the force of the thrust may press the tissues underneath.

In young persons, the chest is mobile and may be compressed during the stabbing. The breast, buttocks and thigh are indented by a full thrust, and the depth of wound may exceed the length of the weapon. Expansion and retraction of the chest during breathing must also be considered. Many of the internal organs are not fixed but have a variable degree of mobiliy. This should be taken into account when estimating the depth of the wounds. After the withdrawal of the weapon, the wound tends to close by expansion of the tissues along the track. The depth should be determined in the operation theatre when the wound is repaired.

The viscera of a dead body on the autopsy table are not in the same positions, as when the same person was alive and in standing position, or was bent over in a state of emotional tension, at the time of an assault. During fight, fright and flight, the victim may be moving or changing position in a variety of postures, which change by the second. When tense, the abdomen is usually contracted, and the distance between the abdominal wall and the spine is reduced. When the same body is on the autopsy table, the abdominal wall is relaxed and this distance increases. Similarly, the anatomical relationship between the lungs, liver and other viscera is not the same as when the person is bent at the hips and when lying flat. In a stab wound on the anterior wall of the chest, the postmortem depth is greater than it was during life, because Of the collapse of the lung. If the stab is on the back of the chest, the depth of the wound will be less, as the lungs will collapse posteriorly.

The force required to inflict stab wound is subjective, and can only be stated in comparative terms, such as slight pressure, moderate force, considerable force, and violent penetration. The depth of stab depends on:

(1) Condition of the knife: The sharpness of the extreme tip of the knife is the most important factor in skin penetration. Once the tip has perforated the skin, the cutting edge is of little importance, and the rest of the blade will pass into the body with ease, without any further force being applied. A thin, slender, double- edged knife will penetrate more deeply than an equally sharp, wide, single-edged blade inserted with the same force. A blunt-pointed instrument requires considerable force to puncture the skin and penetrate the soft tissues.

(2) The resistance offered by the tissues or organs: Apart from bone and calcified cartilage, the skin is most resistant to knife penetration.

(3) Clothing: The amount of clothing and its composition, e.g. multiple layers of tough cloth, leather belts, thick leather jackets, or coats, etc. require greater force.

(4) The speed of thrust of the knife.

(5) Stretched skin is easier to penetrate than lax skin, e.g. chest wall.

(6) When the knife strikes the skin at right angle, it usually penetrates more deeply than when it strikes from some acute angle.

(7) When the knife penetrates the skin rapidly, e.g. if the body falls or runs on to the blade, the momentum of the forward moving body is sufficient to cause fatal injury. However, the knife must be sharp-pointed and held firmly so as to penetrate easily, as a blunt knife held loosely will be turned aside by the approaching body.

A piece of pliable tubing may be introduced gently, and if it goes in easily may reveal the true track. Later, the tubing can be made more rigid and straight by inserting a probe into it. Dissection in the tissues parallel to, but away from the wound, will reveal the track. Radio-opaque material or dyes can be injected into stab wound to demonstrate the wound track by X-rays.

Shape : The size and shape of a stab wound in the skin is dependent on the type of implement, cutting surface, sharpness, width and shape of the weapon, the direction of thrust, the movement of the blade in the wound, cleavage direction, the movement of the person stabbed, and the condition of tension or relaxation of the skin. Stab wound and incised wounds are slit-shaped with two acute angles, or gape open depending on their location and their orientation, with regard to the so- called cleavage lines of Langer. The pattern of fibre arrangement of the dense feltwork of intimately intermingled dermal collagen and elastic fibres is called the cleavage direction or lines of cIea age of the skin, and their linear representation on the skin are called Langers lines, which is almost same in all persons.

Cleavage lines in the dermal layers of skin are mostly arranged in parallel rows. In the extremities they tend to run longitudinally; in the neck and trunk circumferentially. A stab wound which runs parallel to the cleavage lines will remain slit-shaped and narrow and the dimensions of the blade will be represented with considerable accuracy. A stab wound which cuts through the cleavage lines transversely will gape. If the knife is inserted in an oblique plane, the skin defect is wider and the wound may gape asymmetrically and assume a semicircular or crescentic shape.

To ascertain the shape of the instrument, the edges of a wound may be manually approximated with slight twisting or they may be held together with a transparent adhesive tape. The resulting slit is considerably longer than the original oval-shaped wound. This will counter the claim of the defence that the suggested knife could not have produced a stab wound of the type as seen before reconstruction. The dimensions of the gaping wound are not useful to assess the shape of the blade.

The shape of the stab wound usually corresponds to the weapon used, but the shape of the wounds made by the same weapon may differ on different parts of the body.

(1) If a single-edged weapon is used, the surface wound will be triangular or wedge- shaped, and one angle of the wound will be sharp, the other rounded, blunt or squared off. Blunt end of the wound niay have small splits (often in two places) in the skin, so-called “fishtailing”, if the back edge of the blade is stout. Some stab wound caused by single-edged weapon have bilateral pointed ends like those due to double-edged weapons. This is due to:

• The initial penetration by the knife point to a depth of about one cm., first produces a dermal defect with sharp angles at each end. . As the knife penetrates more deeply, the end in contact with the cutting edge of the blade continues to be sharply angulated. The opposite end which is in contact with non-cutting surface of the knife, also remains sharply angulated because the dull surface does not imprint its shape to the skin defect. It merely causes further separation of the skin which continues to be torn along the course of its original direction.
• The knife penetrating the skin at an oblique angle. As the knife perforates, it is pulled down with the cutting- edge cutting through the skin, and the blunt surface of the back of the knife does not impart its shape to the skin defect, as it does not contact it.
• Many single- edged knives have a cutting edge on both sides at the tip.

The initial thrust into the skin will produce a double-pointed stab wound, and as the blade passes through the skin, if it is pulled down slightly, the blunt back portion of the knife will not come in contact with the skin. The serosal planes and muscle fasciae (pleural surface, liver capsule and the pericardial sac) often clearly show the wedge-like shape of a knife. In some single-edged knives, both ends are blunt.

This is caused if the knife penetrates to full length up to the guard, because of ricasso (short, unsharpened section of blade between the cutting edge and guard). By examination of a single wound, it is not possible to say, whether it was caused by a single-edged or double-edged weapon. If multiple stabs are produced by a single- edged weapon, examination of all the stab wounds will reveal the single-edged nature of the weapon.

(2) If a double-edged weapon is used, the wound will be elliptical or slit-like and both angles will be sharp, or pointed. If the knife penetrates to full length up to the guard, one or both edges may be blunt because of ricasso.

(3) A round object like the spear may produce a circular stab wound.

(4) A round blunt-pointed object, such as a pointed stick, or metal rod may produce a circular surface wound with inverted ragged and bruised edges. Foreign material, such as dirt, rust or splinters may be foundin the wound. The blunter the tip of the object, the coarser or more stellate will be the hole it makes.

(5) A pointed square weapon may produce a cross- shaped injury, each of the 4 edges tearing its way through the tissues.

(6) A fall on a pointed article, e.g., pieces of broken glass, will produce a wound with irregular and bruised margins, and ftagments of glass may be found embedded in the soft tissues.

(7) Stab wounds inflicted with a broken bottle, appear as clusters of wounds of different sizes, shapes, and depth, with irregular margins, and varying depth.

(8) Stabbing with a fork produces clusters of 2 or 3 wounds depending upon the number of prongs on the fork.

(9) A screwdriver will produce a slit-like stab wound with squared ends (rectangular) and abraded margins.

(10) Thick relatively blunt-edged blades, e.g., bayonets, may produce cross-shaped stab wounds, because cutting and tearing of the skin occurs simultaneously and at right angles to each other. When a knife is twisted as it is withdrawn from the tissues, the external wound may have a cruciate appearance.

(11) Ice-picks or similar instruments produce stab wounds, resembling small caliber bullet wounds.

(12) Irregularly-shaped stab wound such as L or V-shaped may be mistaken to be produced by two distinct stabbings in the same location. These atypical injuries are produced by stabbing, followed by simultaneous twisting and cutting (rocking), or the victim moving relative to the knife, or by a combination of the two. There will be a primary stab wound with an extension of it, due to the knife edge cutting the skin in a different direction as it exits. Small notches in margins of the skin defects or curving can be produced by the same mechanism. A great number of possibilities capable of causing atypically shaped stab wounds exist, the interpretation of which are usually difficult. (m) If the scissors is closed, the tip of the scissors splits rather than cuts the skin, producing a linear stab wound with abraded margins. Deep penetration will produce ‘Z’-shaped wound. If the screw holding the two blades is projecting, there are small lateral splits in the wound centre. If the two blades of the scissors are separated, each thrust will produce two triangular stab wounds. (n) A knife with a serrated back edge will produce a stab wound, the back edge of which may be torn or ragged. If the knife enters obliquely, serrated abrasions may be seen on the skin adjacent to the end of the wound.

Direction : When the knife penetrates at an angle, the stab wound will have a bevelled margin on one side with undermining (undercut) on the other, so that subcutaneous tissue is visible, indicating the direction from which the knife entered. In solid organs like the liver, the track made by the weapon is better seen. The principal direction should be noted first and other next, e.g., backwards and to the right. If the weapon is partially withdrawn and thrust again in a new direction, two or more punctures are seen in the soft parts with only one external wound. If the wound is perforating, it should be described in sequential order: the stab wound of the entrance, the path of the wound track, and the wound of exit. If the wound is penetrating, the wound of entrance should be described first, then the depth and direction of wound track, and specific termmation.

An example of description of stab wound: Stab wound, wedge-shaped on the right upper chest, placed obliquely, with the inner end lower than the upper outer end. Length was 4 cm. The maximum width at the centre was 5 mm. The centre of the wound was just below the line joining the nipples, being 5 cm. from the midline, 6 cm. from the right nipple, and 18 cm. below right collar bone. The inner end was sharp and outer blunt. The lower margin was undermined. A track is established on the right anterior thoracic wall, passes through the fifth interspace, through upper lobe of right lung to a depth of 7 cm. A right haemothorax of 400 ml. of fluid and clotted blood is present.

Complications : (1) External haemorrhage is slight but there may be marked internal haemorrhage or injuries to internal organs. (2) The wound may get infected due to the foreign material carried into the wound. (3) Air embolism may occur in a stab wound on the neck which penetrates jugular veins. Air is sucked into the vessels due to the negative pressure. (4) Pneumothorax. (5) Asphyxia due to inhalation of blood.

Concealed Puncture Wounds : These are puncture wounds caused on concealed parts of the body, such as nostrils, fontanella, fornix of the upper eyelids, axilla, vagina, rectum, and nape of the neck. Fatal penetrating injuries can be caused without leaving any readily visible external marks, e.g., thrusting a needle or pin into the brain through the fontanelles, through the inner canthus of the eye, or into the medulla through the nape of the neck. These injuries may not be detected unless searched carefully.

Examination : The following points should be noted :

(1) Identification and labelling of cuts and damage to clothing.

(2) Distribution of blood stains.

(3) Removal of clothing, layer by layer.

(4) Identification and labelling of wounds.

(5) Wounds:

• Position (height from heels),
• location (measurements from fixed anatomical landmarks),
• description including margins, size, shape, ends, extension,
• direction,
• depth,
• trauma to viscera,
• estimation of force required,
• foreign bodies.

To indicate the general character of the instrument which inflicted the stab wound, the term incised’ or ‘lacerated’ should be included in the description of the stab wound, e.g., ‘incised-stab wound’, ‘lacerated-stab wound’, etc. The relationship between the wound and weapon can be established by the shape, width, length, and presence of blood on the weapon.

When multiple stab wound are present, they should be numbered and photographed. A sketch or a printed body diagram should be used.

Incised-stab wound: Incised-stab wound is a wound which starts as an incised wound and ends as a stab wound by the sudden thrust of the blade into the body, or starts as a stab wound and becomes incised wound as the knife is pulled out of the body at a shallow angle to the skin surface producing an incised wound. If a nick or a pork-shaped cut is present at the end of the stab wound opposite to the incised portion, then the wound has started as an incised wound and ended as a stab wound. If the fork is at the end of the stab wound where the incised wound arises, then the wound has started as a stab wound.

The external and internal appearances of a stab wound help to give an opinion upon:

(1) dimensions of the weapon,

(2) the type of weapon,

(3) the taper of the blade,

(4) movement of the knife in the wound,

(5) the depth of the wound,

(6) the direction of the stab, and

(7) the amount of force used.

Examination of the Weapon : The doctor should note :

(1) the length, width and thickness of the blade,

(2) whether single-edged or double- edged,

(3) the degree of taper from tip to hilt,

(4) the nature of the back edge in a single-edged weapon, e.g. squared-off, serrated, etc.,

(5) the face of the hilt guard adjacent to the blade,

(6) any grooving, serration or forking of the blade, and

(7) sharpness of the extreme tip of the blade and the cutting edge.

In some cases of stabbing, the blade of the knife may not be bloodstained. In solid organs, bleeding occurs only after the knife is withdrawn, because bleeding is prevented by the pressure of the knife. During the withdrawal of the knife, the muscular and elastic tissue of the solid organs, and the elastic tissue of the skin may contract about the knife, wiping off the blood present on the knife blade. In such cases, analysis of wiping of the blade might still yield sufficient tissue to perform at least limited DNA analysis and typing. The clothing if present, may also wipe off the blood. An injury may cause deep shock and severe circulatory collapse. Subsequently, even if a deeply penetrating stab wound is produced, there may be little bleeding.

Medicolegal Importance :

(1) The shape of the stab wound may indicate the class and type of the weapon which may have caused the injury.

(2) The depth of the wound will indicate the force of penetration.

(3) Direction and dimensions of the stab wound indicate the relative positions of the assailant and the victim.

(4) The age of the injury can be determined.

(5) Position, number and direction of stab wound may indicate manner of production, i.e., suicide, accident, or homicide.

(6) If a broken fragment of weapon is found, it will identify the weapon or will connect an accused person with the crime.

Causes: (1) Striking the body with the edge of sharp-cutting weapon, (2) by drawing the weapon, and (3) by using the weapon like a saw in which case there may be more than one cut in the skin at the beginning of the incised wound which merge into one at the end.

A curved weapon like a sickle, produces a stab from the pointed end, and incised wound from the blade, sometimes with an intervening intact skin. When the skin becomes folded under the cutting edge of the weapon, a single movement of a sharp weapon may produce a series of incised wound, separated one from another by bridges of normal skin.

Characters : (1)Margins : The edges are cleancut, well-defined and usually everted. The edges may be inverted, if a thin layer of muscle fibres is adherent to the skin as in the scrotum. The edges are free from contusions and abrasions. A dull irregular-edged or nicked cutting edge may produce a incised wound with irregular, contused, and/or abraded margins, as the wound is caused more by the pressure applied by the weapon than by the cutting edge. A serrated knife may produce a saw-toothed cut on the body, if the blade passes obliquely or at shallow angle. The depth of the wound will not show bridging tissue.

(2) Width : The width is greater than the edge of the weapon causing it, due to retraction of the divided tissues. Shaking of the blade tends to make the wound wider than the weapon.

(3) Length : The length is greater than its width and depth, and has no relation to the cutting edge of the weapon, for it may be drawn to any distance. When the skin becomes folded under the cutting edge of the weapon, a single movement of the weapon may produce a series of incised wound separated one from another by bridges of normal skin.

(4) Shape: It is usually spindle-shaped due to greater retraction of the edges in the centre. Gaping is greater if the underlying muscle fibres have been cut transversely or obliquely, and less when cut longitudinally. Incised wound crossing irregular surfaces may be irregular in depth, but will be linear. The wound may take zig-zag course if the skin is loosely attached as in axillary fold, because the skin is pushed in front of the blade before it is cut. If the blade is curved, the edges will be crescentic. If the surface is convex, the straight-bladed weapon may also produce a crescentic wound.

(5) Haemorrhage: As the vessels are cut cleanly, the haemorrhage is more. If the artery is completely cut, the bleeding will be more. Spurting of blood occurs if an artery is cut.

(6) Direction: Incised wound is deeper at the beginning, because more pressure is exerted on the knife at this point. This is known as the head of the wound. Towards the end of the cut the wound becomes increasingly shallow, till finally as the knife leaves the tissues the skin alone is cut. This is known as the tailing of the wound, and indicates the direction in which the cut was made.

(7) Bevelling cut : If the blade of weapon enters obliquely, the tissues will be visible at one margin, and the other margin will be undermined, and if the blade is nearly horizontal, a flap wound is caused. Bevelling can be produced by sharp weapon only. It is usually homicidal and may indicate the relative position of the assailant and the victim.

Age of incised wound : In an uncomplicated wound, healing occurs as follows: Fresh: Haematoma formation. 12 hours: The edges are red, swollen and adherent with blood and lymph; leucocytic infiltration. 24 hours : A continuous layer of endothelial cells covers the surface; overlying this a crust or scab of dried clot is seen.

Histopathology: Few minutes: Dilatation of capillaries and margination and emigration of neutrophils, reactive changes in the tissue histiocytes and swelling of the vascular endothelium. 12 hours: Reactive changes occur in the firlioblasts at the site of injury within few hours; monocytes’ appear in the exudate. 15 hours: Monocytes begin to undergo mitotic division. 24 hours: Epithelium begins to grow at the edges. Vascular buds begin to form. 72 hours: Vascularised granulation tissue is formed. 4 to 5 days: New fibrils are formed. One week: Scar formation in small incised wound. The above changes are considerably modified if infection of the wound occurs.

In healing by second intention, inflammatory reaction is more intense and much larger amounts of granulation tissue are formed resulting in greater mass of scar tissue.

Wounds by Glass : Wounds produced by glass are lacerated, but can resemble incised and stab wounds. If a sharp-pointed piece of glass enters by its point, the wound has a stab-like appearance. Margins of the wound will almost always show tiny side cuts due to irregularities of the glass. Particles of glass may be found in the wound. Assault with broken glasses or bottles show multiple irregular incised-type wounds of variable depth and severity.

Medicolegal Importance: (1) They indicate the nature of weapon (sharp-edged). (2) The age of the injury can be determined. (3) They give an idea about the direction of the force. (4) Position and character of wounds may indicate mode of production, i.e., suicide, accident, homicide.

Circumstances of Incised Injuries : Suicide:The important features of self-inflicted wounds are:(1) They are multiple and parallel or nearly so, in any one area. (2) They are uniform in depth and direction. (3) They are relatively minor. (4) The fatal wounds are present on several limited accessible areas of the body, such as front of the neck, wrists, groin, and occasionally on the back of legs or on chest. (5) Hesitation marks or tentative cuts or trial wounds: They are cuts which are multiple, small and superficial often involving only the skin and are seen at the beginning of the incised wound.

The sites of election of suicidal incised wound are: throat, wrist and front of chest When preliminary incisions are inflicted with some violence they may be few, but commonly they are superficial and multiple. The fatal incisions are usually made with great violence, and the large gaping wound produced by suicide should not be mistaken for homicidal wounds. When a safety razor blade is used, unintentional cuts are found on the fingers, where the blade has been gripped.

SUICIDAL incised wound of extremities are usually found on the flexor surface of the wrists, outer side of the left arm, and forearm, the front and outer side of the thighs, and the front of the abdomen and chest. Fatal incised wounds of the arms are almost always suicidal. Suicidal wounds of chest are usually on the left side and directed downwards and inwards. A wound caused by running on knife tends to be more horizontal in direction. A person who commits suicide usually exposes the portion of the body to be incised, e.g. he may open his collar before cutting his throat, or pull up his shirt before cutting his chest or abdomen. Suicides usually do not injure the face.

HOMICIDAL WOUNDS: They are usually multiple and can occur in any region of the body. Wounds of the chest are usually present over a wider area and are more horizontal. They may be directed from below upwards which is rarely seen in suicidal wounds. Incised wound situated on the back, or in such a position as cannot be easily reached by a suicide, are homicidal. Incised wound on nose, ears and genitals are usually homicidal, and are inflicted on account of jealousy or revenge in cases of adultery, causing disfiguration. Cut-throat wounds cause immediate death from haemorrhage, air embolism, or inhalation of effused blood into the respiratory tract.

ACCIDENTAL incised wound are common usually in the home or workshop, and are of a minor nature. They may be caused by falling upon a sharpcutting weapon held in the hand, or upon a sharppointed object or by a sharp piece of broken glass. They may be situated anywhere on the body, but are commonly seen about the hands.

Some mentally disordered persons may inflict hundreds of small incised wound upon themselves. A knife, razor or broken glass may be used and a large number of cuts produced on the arms which may cross each other in groups. Small stabs may be produced on the chest or temples. Paranoid schizophrenics with a strong religious flavour to their delusions may remove penis, scrotum, and testes. Ears and nose may be mutilated.

In a decomposed body, it is difficult to differentiate a laceration from an incised wound. When a body with incised wound, stab wounds, or lacerations is immersed in water soon after infliction of injuries, the blood in the wounds is lysed by water and passes into the water, and whether the injuries are antemortem or postmortem cannot be made out.

CHOP incised wound (Slash wounds) : They are deep gaping wounds caused by a blow with the sharp-cutting edge of a fairly heavy weapon, like a hatchet, an axe, sword, broad heavy knife, or meat cleaver. The dimensions of the wound correspond to crosssection of penetrating blade. The margins are sharp and may show slight abrasion and bruising with marked destruction of underlying organs. If the edge is blunt, the margins are ragged and bruised. Undermining occurs in the direction towards which the chop is made. When the whole blade strikes the body at the same time, the depth may be same throughout the wound.

Usually the lower end (heel) of the axe strikes the surface first, which produces a deeper incised wound than the upper (toe) end. The deeper end indicates the position of the assailant. In the skull, the undermined edge of the fracture defect is the direction in which the force is exerted, and the slanted edge is the side from which the force was directed. In case of long bones, the bone fragments get loosened on the opposite side of the force.

A twisting force, after the chopping weapon has been embedded in bone, and as it is being removed can cause splintering of the bone, particularly near the ends of the chop incised wound. If the extremities are attacked, there may be complete or incomplete amputation of the fingers or other bones, and the joints may be separated or disarticulated. Incised wound on the head and trunk are usually associated with injuries to important structures and are fatal. The cranium may be depressed, but if the weapon strikes obliquely, a piece of the skull may be removed. If the chopping blow is tangential, a disk- shaped portion of bone or skin or soft tissue may be cut away. The neck may be almost completely separated.

Most of these injuries are homicidal and usually inflicted on the exposed protions of the body like the head, face, neck, shoulders and extremities.

Accidental injuries are caused by power fans, band saws or ship or airplane propellers, which may lacerate the soft tissues extensively or amputate parts of the body. Suicidal chop injuries are very rare.