Firearm, Explosive, Thermal and Electrical Injuries

Source of Energy

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Energy Transfer

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Tissue Effect

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Injury Pattern

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Forensic Examination

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Interpretation

Firearm Injury: Weapon to Wound

Propellant ignition → rapidly expanding gases → projectile acceleration → kinetic energy transferred to tissue → permanent wound track with additional tissue disruption.

Firing range → amount of flame, smoke and unburnt powder reaching skin → surrounding wound features → estimation of probable range.

Entry, Exit and Bone Beveling

Projectile enters skin → inward tissue disruption → characteristic entry morphology; projectile exits → outward tissue disruption → exit wound morphology.

Cranial penetration → beveling of bone → helps infer the direction of projectile travel.

Explosion: Pressure to Multisystem Injury

Blast pressure wave → greatest effect on gas-containing organs → internal injury even when external trauma is limited.

Flying fragments, body displacement and associated heat → penetrating, blunt and thermal injuries → multiple possible causes of death.

Thermal and Electrical Energy

Dry heat or hot liquid → tissue protein injury → burn or scald pattern whose appearance depends on the source and extent of exposure.

Electric current through the body → electrical and thermal tissue damage → external electrical marks may accompany serious internal or fatal effects; lightning can produce a distinctive high-energy electrical injury.

⭐ Firearm injury reflects energy transfer: projectile velocity, behavior and interaction with tissue determine the amount of damage rather than wound diameter alone.

Internal, external and terminal ballistics describe different stages of projectile behavior; terminal ballistics links projectile impact with tissue injury.

⭐ Findings around a firearm entry wound → effects of flame, smoke and powder → provide information about the probable range of fire.

Entry and exit wounds must be interpreted together with tissue and bone findings; beveling can assist in determining the direction of a projectile through skull bone.

⭐ Explosion → blast pressure + fragments + body displacement + heat → combined internal, penetrating, blunt and thermal trauma, explaining the variable causes of death.

Burns result mainly from dry heat, whereas scalds result from hot liquids or steam → different modes of heat transfer produce different external injury patterns.

⭐ Electrocution → passage of electric current through the body → electrical and thermal tissue injury; fatality may occur even when external findings are limited.

Lightning is a high-energy natural electrical discharge → characteristic external findings may coexist with severe internal physiological disturbance and sudden death.