Firearm-injury assessment integrates medical findings with clothing, scene and suitable firearms examination. Wounds and residues can inform questions about passage and range without uniquely identifying the weapon, shooter or manner.
Distance categories require relevant conditions and, where appropriate, comparison test firing. No universal 15- or 60-centimetre boundary or pellet-spread rule applies.
By the end of this topic you will be able to:
- Explain ammunition components and possible injury findings.
- Distinguish entrance, exit and track interpretation limits.
- Evaluate range using appropriate comparative conditions.
- Smooth-bore firearm
- An unrifled bore; load and projectile behaviour depend on the actual weapon and ammunition.
- Rifled firearm
- A bore with spiral features; represented marks require suitable comparison and interpretation.
- Abrasion collar
- Abraded tissue that can occur around entrances and some supported exits; not an absolute classifier.
- Tattooing (stippling)
- Possible powder-related punctate findings requiring differential and contextual assessment.
- Gunshot residue (GSR)
- Discharge-related material whose composition, deposition and transfer vary.
- Country-made firearm (katta)
- A regional term for locally made weapons, not a guarantee of bore, load or performance.
Firearm Classes and Jurisdiction-Specific Law
Distinguish rifled and smooth bores, ammunition and actual firearm condition. Smooth-bore weapons can fire different loads; locally made weapons are not one uniform category.
Legal classification and possession requirements vary. India’s Arms Act remains distinct from the BNS.
Ammunition Components and Gunshot Evidence
Projectile, propellant and primer components can contribute different evidence. Ammunition composition varies; all residues are not a fixed lead-antimony-barium mixture.
A cartridge can include a case, primer, propellant and projectile, with load-dependent components such as wads or multiple pellets. These can contribute different scene, clothing and medical findings. Their absence or presence depends on collection, event conditions and the actual ammunition.
Entry Wound by Range
Contact effects, soot, stippling and other findings need context. Abrasion collars are not present at every entrance, and supported exits can show abrasion.
Possible entry findings can include marginal abrasion and discharge-related effects. Contact, soot and powder-related findings need differentiation from damage, contamination and treatment. A supported exit can show abrasion, so a single collar should not decide the complete direction of passage.
Exit Wound and the Track Between Them
Track interpretation considers anatomy, deformation, deflection and movement. The body’s final position does not necessarily reproduce the position at discharge.
Shotgun and Rifled-Weapon Range Specifics
Qualified comparison testing should use relevant firearm, ammunition, target and conditions where available. Report the supported bracket and limits, not a universal distance formula.
Distance determination can compare observed residues or damage with known-distance tests under relevant conditions. The result may be a supported range or a limitation, not an exact number. Clothing and intervening materials can change what reaches skin.
GSR, Medico-Legal Differentiation and Bullet Forwarding
Preserve clothing, projectiles and suitable residue samples with their identity and condition. Residue presence can involve transfer or environmental sources; absence alone does not determine range or exclude discharge.
Check Your Understanding
Sources
- 1.Death Investigation: A Guide for the Scene Investigator (2024) · National Institute of Justice
- 2.Autopsy guidelines series · Royal College of Pathologists
- 3.Distance Determination · National Institute of Justice