The Development of a Gas Chromatography/Mass Spectrometry (GC/MS) Method for the Separation and Identification of Components of Organic Gunshot Residue and Its Use as a Forensic Tool for Association of Firearms Related Evidence

Abstract

The use of methods that are not only scientifically sound but also conform to the precepts of the Frye and Daubert legal standards is paramount in the forensic science disciplines. This research develops a method of analysis that can be used by the smaller forensic crime laboratory in the analysis of evidence associated with smokeless powder composition and its organic gunshot residue (OGSR). The method specifically focuses on the separation and identification of the organic additives of the propellant mixture found in handgun ammunitions and their discharge products via gas chromatography/mass spectrometry (GC/MS) using the SIM Mode. The specific ammunition used in this research is Federal Classic 9 mm Luger, 115 gr Hi-Shok. The developed method addresses the following forensic concerns: 1. The identification of organic additive components of smokeless powder that have been removed from the hands of the shooter and compared with the residues remaining in the spent cartridge casings that may be found at a crime scene as well as the components of the unburned propellant. 2. The method demonstrates the use of a proprietary solvent that enhances the collection of the OGSR residues. 3. The method defines the criteria that can be used to determine if the composite analysis of the residue is indicative of the discharge of a firearm. 4. The method studies the longevity/stability of the residues post-discharge and the changes compositional profile, if any. The use of this method in conjunction with the analysis of the inorganic particulate matter will enhance the overall ability of forensic laboratories to identify gunshot residue discharges.