Organic Gunshot Residue: Detection, Identification, and Characterization for Forensic Purposes

The major focus of this thesis was to explore methods for the detection, identification, and characterization of organic gunshot residues (OGSRs) for forensic purposes using various spectroscopic techniques. There are four major projects detailed in this thesis. The first project details the development of a novel-two step method for the detection and identification of organic gunshot residues using fluorescence spectroscopy for detection and Raman spectroscopy as a confirmatory step. The second chapter builds upon the study conducted in the first chapter by applying the novel-two step method covered in the first chapter to OGSRs directly fired into cloth substrates. This study also further explored the usage of 3-D Raman terrain mapping techniques in order to attain spectra of OGSR particles embedded in cloth substrates. The third chapter investigated the usage of Raman spectroscopy and Laser-induced breakdown spectroscopy (LIBS) to differentiate between OGSRs stemming from closely related types of ammunition stemming from the same caliber and ammunition types. The final chapter details a study in which smokeless powders (the major precursor to OGSRs) were analyzed via Raman spectroscopy and differentiated by ammunition manufacturer and caliber using a “hierarchical” modelling system involving advanced chemometric techniques.