Forensic analysis of gunshot residue by using secondary ion mass spectrometry

Forensic analysis of gunshot residue includes examining the light particles present in incandescent gaseous material as a result of firing a gun. After shooting they sediment in the surroundings of the shooter. The primer residues that contain a specific content of elements are traced in gunshot residues. By proving their presence, we are able to identify the shooter and affirm his/her relationship to the detained gun. In this work, we focused on the analysis of gunshot residue in three different primers in cartridge cases and fingerprints containing the particles from the gun barrel. The analysis was performed using the secondary ion mass spectrometry. We determined the elemental abundance by recording the mass spectra and their specific peaks as well as their oxidated forms which confirmed their presence in samples. The recorded abundance of elements was compared to the reference abundance provided directly from forensic ballistics. We showed secondary ion mass spectrometry to be a suitable complementary technique along commonly used methods for the gunshot residue analysis. (authors)