Gunshot Residue Analysis

Gunshot Residue Analysis

Gunshot residues (GSR) are produced and deposited on the person who discharges a firearm and/or in its proximity. Tests of skin and clothes for the presence of gun-residual particles help to determine if a person was near the discharge. The chemical composition of GSR is determined by the primer. Most ammunition uses primer composed of lead styphnate, barium nitrate and antimony sulfide; therefore, particles composed of Pb, Ba and Sb are used as an indicator for GSR. Scanning Electron Microscopy (SEM) with energy-dispersive X-ray spectroscopy is the standard method for the GSR analysis. Though reliable, SEM is time-consuming and offers a very low throughput.  

Owing to its fast and simultaneous multi-element detection capabilities, the icpTOF operated in single-particle mode is a promising candidate for the analysis and characterization of inorganic gunshot residue (IGSR). Indeed, not only does the icpTOF identify GSR particles based on their Pb-Ba-Sb fingerprint, but it also provides better statistics thanks to its speed of analysis. Following the same quantification approach as for nanoparticle analysis, the gunshot particles can be analyzed in terms of mass and particle number concentration. Preliminary results show that this technique holds great promises for GSR sample identification and characterization.