14.11 Gunshot wounds

Question 1

What is a firearm?

Question 2

Permanant cavity

Question 3

Temporary cavity

Question 4

Changes caused by the bullet:

Answer 4

• The central, punched-out defect
  -The abrasion ring
• The grease ring/smudge ring or dirt collar
• Contusion
• Surrounding defects

Question 5

Discuss the central, punched out defect.

Question 6

Discuss the abrasion ring.

Question 7

Discuss the grease ring.

Question 8

Discuss contusion.

Question 9

Discuss the surrounding defects.

Question 10

What does the heat and gas cause?

Answer 10

• Burning of the skin
• Hair loss
• ‘Pin head’ appearance of the hair
• The distance on which the effects of heat can be seen on the skin is about 10-20 mm
  away from the gun

Question 11

What does smoke and soot cause?

Answer 11

• Greyish / Black discolouration (deposition) around and in wound.
• Distance once again varies according to Di Mayo (20-30 cm) and according to Knight ± 15
  cm. This once again is for hand weapons. For shoulder weapons the values must be
  doubled.
• Can be washed off the skin.

Question 12

What does the burning or unburnt particles of a propellant cause?

Answer 12

• Tattooing (refer also peppering, speckling etc.).
• Ante mortem phenomena
• Distance: ± 50 cm (Knight - hand weapons)

Question 13

Changes to wounds that are not caused by the bullet or components that leave the barrel of the gun, or the bullet.

Answer 13

• Pieces of clothing can be present in wound.
• ­[CO] than at exit wound (no need to worry about it)
• Usually smaller than exit wound.

Question 14

Characteristics of an exit wound:

Answer 14

• Shapes vary widely
• Surrounding bruising may be present
  May exhibit a collar of abrasion (atypical or shored exit wound)

Question 15

Components of: Shape wounds vary widely:

Answer 15

• Irregular and torn
• Ragged appearance
• Lacerated shape
  -Sometimes a round shape

Question 16

Characteristics of an exit wound.

Answer 16

• No smudge ring.
• No singeing, soot deposition, tattooing
• Decreased [CO] than in entrance wound
• No clothing / foreign material in wound
• Borders sometimes beveled outwards (be careful)
• Usually larger than entrance wound due to bigger contact area and secondary projectiles like bone.

Question 17

Characteristics of a contact gunshot wound

Answer 17

• Overlying bony tissue (e.g. skull) causes
  a stellate, torn type of wound, sometimes with imprint abrasion. This is due to gas cavity formation between skin and bone.
• Over non-bony areas (e.g. abdominal wall,
  thigh)
• Sometimes imprint abrasion wound (especially
  with high velocity firearm. Wound usually not
  torn.

Question 18

Diagram of rifled weapon wounds vs short gun wounds