GSR (Gunshot Residue)
Definition
Primer-combustion products (classically lead-barium-antimony compounds, now also non-lead formulations) deposited on the bone surface at close or contact range; detected by SEM-EDX analysis and used as an independent range indicator complementing the osteological morphological findings.
- Full form
- Gunshot residue
- Deposited on
- Bone surface at close or contact range
- Classic elements
- Lead, barium, antimony
- Detection method
- SEM-EDX analysis
- Forensic value
- Independent range indicator alongside osteological findings
Common questions
Why is GSR on bone treated as independent evidence rather than just confirming the wound morphology?+
Beveling and fracture patterns on bone estimate range and direction from physical damage alone, while GSR deposition is a separate chemical trace tied to actual muzzle-to-target distance. When both point to the same conclusion, confidence in the range estimate rises considerably.
Does the absence of GSR on skeletal remains rule out a close-range shot?+
Not reliably. GSR particles are fragile and can be lost to weathering, water immersion, decomposition fluid, or handling during recovery and cleaning of the bone, so a negative result is weaker evidence than a positive one and must be interpreted alongside the physical wound characteristics.
Related terms
- Bearing Surface Diameter
- The diameter of the projectile face in contact with the bone surface at the moment of impact; smaller than the resulting defect...
- Contact Wound
- A firearm wound produced when the muzzle is pressed against or within a few centimetres of the target surface. Characterised by a...
- External Beveling
- The cone-shaped defect geometry at an exit gunshot wound in bone: the inner table diameter (entry face of the defect) is smaller...
- Internal Beveling
- The cone-shaped defect geometry at an entrance gunshot wound in bone: the outer table diameter (entry face) is smaller than the inner...
- Keyhole Defect
- An asymmetric gunshot defect produced by a projectile striking bone at a shallow angle; one end shows a conventional beveled entry geometry...
- Puppe's Rule
- The 1994 formalisation of the principle that radial fractures from a subsequent gunshot terminate at fracture lines already produced by a prior...
- Secondary Projectile
- A bone fragment or other material driven at high velocity through adjacent tissue by the primary projectile's passage through bone; produces irregular,...
- Stellate Fracture
- A set of radial cracks extending outward from the main gunshot defect, produced by compressed propellant gas pressure radiating under the scalp...
- Trajectory Reconstruction
- The forensic procedure that integrates the osteological bevel direction, angle-of-impact estimate, and the physical scene evidence to reconstruct the relative positions of...