A. Phenolphthalein test.
B. Dermal nitrate test.
C. Benzidine test.
D. H2 activation test.
Ans:B. Dermal nitrate test.
The image shown is of a Gunshot.
- Incised wound
- Puncture(Stab Wound)
- Firearm entrance wounds are typically round to oval, with smooth edges and a zone of epidermal abrasion surrounding the wound edge.
- Surrounding skin dragged in
- Categorized based on range
- Muzzle is pressed against the skin when fired
- Impression of muzzle burned around entrance
- When the muzzle of a firearm is held firmly against the skin of a victim as it is fired, a hard contact wound results. In this wound, a dark zone of soot (carbon) deposition is present around the edge of the entrance wound.This soot is seared into the skin by hot gases exiting the firearm muzzle and cannot be completely washed away from the wound. It may also be possible to discern a cherry red color of the underlying soft tissues due to the carboxyhemoglobin formed when carbon monoxide that is formed from the burning powder charge is injected into the tissues with the muzzle blast.
- In areas of “loose” skin (abdomen, chest): circular wound with blackened, seared skin margins
- On head, where the scalp is tightly covering the skull, entry wounds can have several different appearances:
- Round wound with blackened, seared skin margins
- Stellate shaped wound, due to tearing of skin from expanding gas dissecting between the scalp and skull
- Near contact(6-8 inches): muzzle of the gun is held a short distance from the skin (< 1 cm from skin with handguns)
- Appears as circular wound with blackened and seared edges that are wider than seen with contact wounds.
- Soot may be deposited loosely on the skin, it may be largely washed away during cleaning of blood from the wound.
- Intermediate((1-3 feets)): defined by the presence of stippling (“powder tattooing”) on the skin surrounding the entry wound
- Stippling is due to unburned powder grains exiting from the gun causing pinpoint abrasions on the skin; these are not burns
- Distant(more than 3 feets): No soot or burning of wound margins
- Appear as round wounds with sharp margins and an abrasion ring on the surrounding skin
- Skin punched out.
- Exit wounds are usually irregular, have no abrasion rim, and do not display soot deposition or stippling.
Gunshot residues are detected by:
- Dermal nitrate test
- Neutron activation analysis
- Atomic absorption spectrophotometry
- Scanning electron microscopy with X-ray analyzer