What is GSR?

• A. General Surface Residue
• B. Gasoline Solvent Residue
• C. Glass Shatter Residue
• D. Gun Shot Residue

Answer: (D)

Gun Shot Residue refers to the tiny particles and vapors produced when a firearm is discharged. It includes primer residues from the cartridge—primarily lead, barium, and antimony—along with unburned or partially burned powder particles and soot that are ejected with the shot. These residues can cling to the shooter’s hands, clothing, or nearby surfaces, and may also be found on the firearm or objects in close proximity. In forensic analysis, GSR is detected using chemical tests and instrumental methods like SEM-EDS to identify the distinctive elemental makeup and particle morphology. The key idea is that finding GSR on a person or object can support that they fired a gun or handled a recently fired firearm, especially at close range, but absence isn’t definitive proof of innocence or guilt because residues can be transferred, removed, or degraded over time. Other types of residues described by unrelated phrases do not capture the specific remnants produced by firearm discharge.