Firearm wounds

Introduction

• Upto 2 yards (near shot), the appearance of entry wound is similar in both rifled weapon (rifle, revolver, pistol) and shotgun 

Firearm injuries result from the

Due to projectile (e.g. bullet/pellets)

Wound of entry and exit Abrasion collar/contusion collar.

 Due to associates of projectile

Heat	Scorching/charring of skin
Gun powder particles (unburnt and partly burnt	Tattooing
Wads	Independent impact abrasions and/or contusions
Flame	Burning (singeing) of hair, and burning/melting/ironing of clothes.
Smoke and fine carbon particles	Soot or blackening and smoke deposition (smudging/fouling).

Contact wound 

• Results in a circular entrance wound that is about the size of the muzzle.
• All the discharges from muzzle are blown into the track taken by bullet.
• Marking of muzzle end may be present on body part and there may be muzzle end imprint abrasion due to pushing of skin against muzzle end by gases.
• Single wound with everted margin
• Cruciate cruciform or stellate in shape.
• There will commonly be smoke soiling of at least some of the margin of the wound.
• If muzzle end is pressed firmly, soiling (blackening and tattooing) or burning are there only inside the wound tract not outside
• Charring of skin seen
• Blast (burst) effect:
• Formation of gases under pressure leads to tearing and eversion of skin, laceration of deeper tissues, fragmentation of bone and burst opening of skull.
• The wads or plastic cup will usually be recovered along the wound track.
• Due to carboxyhemoglobin, the tissues along the wound track is cherry red color.

Close discharge (upto 6 inches)

• Single entery wound which is circular, or elliptical (there are no separate pellete holes in shotgun) and inverted margins
• Burning/melting/ironing of clothes
• More smoke soiling of wound can occur, and burning of skin with singeing and clubbing of melted hairs can be seen around the wound.
• There is also, very commonly, powder ‘tattooing’ of the skin around the entry wound. 
• This tattooing is due to burnt and burning flakes of propellant causing tiny burns on the skin and cannot be washed off.
• Wads will commonly be found in the wound.
• Collars

Three collars are present, encircling the entry wound  

Abrasion/contusion collar	Outer most Due to abrasion/contusion caused by projectile.
Dirt/Smudge/grease collar	Inside to abrasion/contusion collar Caused by oil from the barrel or dust from the atmosphere, carried by the bullet.
Lead collar	Inside the dirt/grease collar and around the main entry hole. Seen only in naked bullet, where lead particles from the bullet get deposited internal to dirt collar.

Intermediate ranges (between 6 inches to 6 feet/ yards)

• Body is within the range of gun powder, but outside the range of flame.
• Only differences from close range are: 

Long ranges (beyond six feet/2 yards)

Rifle wounds:

• No burning (Singeing), scrotching of skin, blackening smudging and tattooing
• Presence of 3 collars : (i) Abrasion/contusion collar, (ii) Grease/dirt collar, and (iii) Lead collar (in naked bullet).

Shotgun

• Upto 5 yards
• Wadding injury 
• At 3-8 yards
• beside the main entry wounds, there are injuries due to other pellets. 
• Beyond 8 yard
• Multiple entry wounds are seen due to individual pellet as all pellets are dispersed

Exit wound

Shotgun

• Exit wounds are seen when fired into the head, neck or mouth. 
• The exit wound in these cases may be a huge ragged aperture, especially in the head, where the skull may virtually explode.
• The spread of shot will begin, 
• Often called a ‘rat-hole’ because of the nibbled edges, the same appearance is also called ‘scalloping’ .
• Separate injuries m/b caused by the wads or plastic shot
• Satellite pellet holes begin to be seen around the main central wound at a range of about 2–3 m.

• In a firearm injury, there is burning, blackening, tattooing around the wound, along with the cherry red colour of the surrounding tissues and is cruciate in shape, the injury is close shot injury.
• Stellate wound is produced with firearm in contact shot.
• In a firearm injury, blackening seen around the entry wound is due to smoke
• Tattooing in entry wound of a firearm injury is due to gunpowder.
• The skull was burst open, charring and cherry red colouration in the track inside. Range of the shot is contact shot.
• ‘Rat hole’ appearance of entry wound of firearm is seen in near range of shotgun.
• In firearm entry wound, arrangement of abrasion collar, dirt collar and tattooing from inside to outside: Dirt collar, abrasion collar, tattooing
• Abrasion collar is seen in entry wound
• Bullet entry wound, for bullet entering at acute angle is identified by oval shape of abrasion collar
• Harrison-Gilroy test can detect gunshot residue
• Bullet entry wound in skull
• Punched in hole in outer table
• Inner table shows bevelling surface
• Wound is funnel-shaped with the funnel opening in the direction in which the bullet is travelling
• exit wound of a bullet
• Bevelled
• Everted
• No COHb