Characterization of lead-free gunshot residue analogs

Abstract

Modern forensic analyses of inorganic gunshot residues rely on the detection of three key elements from the primer: barium, antimony, and lead. However, recent environmental concerns are trending toward an industry-wide shift to the manufacture and distribution of lead-free ammunition. Consequently, this change will require new methods that can be used to fully characterize the composition of lead-free gunshot residues. Spectrochemical analysis of simulated lead-free gunshot residues, in a proof of concept study, was used to identify statistically significant analytical markers present in each composition by Laser-Induced Breakdown Spectroscopy. Rates of error associated with each simulation were determined by leave-one-out cross-validation. Laser-Induced Breakdown Spectroscopy proved to be an effective and rapid screening method in the analysis of simulations of lead-free gunshot residues prior to confirmatory testing by Scanning Electron Microscopy-Energy Dispersive X-ray Spectroscopy.