Gunshot Residue (GSR)
Definition
Microscopic particulate residue containing antimony, barium and lead deposited on the shooter's hand, face and clothing at discharge. Collected by adhesive lift or swab and analysed by SEM-EDX.
- Full form
- Gunshot residue
- Composition
- Antimony, barium, lead particulate
- Deposited on
- Shooter's hand, face and clothing
- Collection
- Adhesive lift or swab
- Analysis
- SEM-EDX
Common questions
Why does GSR collection have a narrow time window?+
GSR particles sit loosely on skin and clothing and are readily removed by washing, sweating, rubbing against surfaces, or normal activity, so laboratories generally recommend sampling within a few hours of the incident to avoid a false negative from residue simply falling away.
Can GSR on someone's hand prove they fired the weapon?+
Not on its own. GSR can transfer through secondary contact, such as touching a recently fired gun, being near a discharge, or handling contaminated objects, so a positive result indicates possible proximity to a discharge rather than conclusively proving the person pulled the trigger.
Related terms
- Abrasion Collar
- The rim of abraded, dried skin surrounding a gunshot entry wound, produced by the bullet stretching the skin inward before perforation. Width...
- Country-Made Firearm (Katta)
- Locally manufactured, usually smooth-bore, single-shot weapon common in Indian murder cases. Low chamber pressure, inconsistent ammunition, atypical wound patterns.
- Rifled Firearm
- A firearm whose bore has spiral grooves that spin the projectile for stability (rifle, handgun). The rifling leaves class-characteristic land-and-groove marks on...
- Smooth-Bore Firearm
- A firearm with an unrifled barrel (e.g. shotgun, country-made katta). Fires pellets or shot; produces dispersion patterns rather than a single projectile...
- Tattooing (Stippling)
- Punctate, non-wipeable haemorrhagic specks around an entry wound, caused by unburnt and partly burnt powder grains impacting the skin. A close- to...