Firearm:Tests, Phenomenons and Suicide VS Homicide

Ans. Entry wound is beveled in the outer table of skull

Ans.B. Gunshot injury

Kennedy phenomenon- surgical alteration or suturing of gunshot wounds creates problems.

The evaluation of the gunshot wound, whether it was an entrance or an exit wound becomes difficult.  

Kennedy Phenomenon is a surgical intervention of firearm wound resulting in an artifact and hence making the wound difficult to interpret during autopsy as happened in 35th president of United States John F Kennedy’s assassination case in 1963.

Ans. Kennedy phenomenon

Kennedy Phenomenon: Surgical alteration or suturing of gunshot wounds creates problems. The evaluation of
the wound, whether it was an entrance or an exit wound becomes diffrcult.’

Ans. Dermal nitrate test

Dermal nitrate/ paraffin/diphenylamine test:

• It is used to detect firearm residues on the hands of the subject.
• In this, the hands are coated with a layer of liquid paraffin. After cooling, the casts are removed & treated with an acid
• the solution of diphenylamine, a reagent used to detect nitrates & nitrites that originate from gunpowder & is deposited on the
• the skin of the person who has fired the shot.
• A positive test is indicated by the presence of blue flakes in the paraffin.

Ans: B.)Dermal nitrate test.

The image shown is of a Gunshot.

Wound Categories

• Abrasion
• Bruise
• Laceration
• Incised wound
• Puncture(Stab Wound)
• Gunshot

 Gunshot injury

Entrance wounds

• 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 the range

Contact Wounds:

• The muzzle is pressed against the skin when fired
• The impression of muzzle burned around the 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 the 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 the skin with handguns)
• Appears as a 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 the cleaning of blood from the wound.
• Intermediate((1-3 feet)): 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 feet): No soot or burning of wound margins
• Appear as round wounds with sharp margins and an abrasion ring on the surrounding skin

Exit wound:

• 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