Strengthening Scientific Foundations for Advancing Best Practices in the Collection, Storage, Analysis, and Interpretation of Organic and Inorganic Gunshot Residues

The U.S. gun epidemic requires an immediate reaction from the criminal justice system to manage workloads and adapt operations. Thus, technology advances for accurate reconstruction of events, prompt apprehensions, and meaningful data sharing are critical for timely justice and increased public safety. Identifying traces of gunshot residue (GSR) is one of the forensic services of great interest in these investigations. Nonetheless, essential information to make informed decisions about recovery at the crime scene, safeguarding the integrity of the evidence, and evaluating the evidence under competing propositions is still needed. Thus, this proposal aims to provide solutions to those needs by enhancing current capacity through (a) technology innovation, (b) enhancing the technical skills of the workforce, and (c) increasing knowledge of GSR transfer and persistence.  The study addresses a primary demand to include organic constituents (OGSR) in the workflow for increased confidence in the results. The main goal is to establish scientific foundations for best practices for the collective recovery, preservation, storage, analysis, and interpretation of IGSR and OGSR. We propose to do that through four specific tasks based on the substantial knowledge gained in the past six years and strategic partnerships with industry, academia (the University of Auckland, Statistics), and practitioners (New Jersey State Police). The study complements conventional SEM-EDS with modern methods previously developed in our group¾ LIBS and electrochemical sensors that provide an unprecedented speed of analysis and accuracy for screening testing at the laboratory and onsite, and LCMSMS. Also, novel methods using laser scattering, high-speed cameras, particle counter samplers, and both human shooters and synthetic skin models will provide unique perspectives on GSR creation, evolution, deposition, stability, and transfer dynamics.

The first task is to develop criteria for preservation and suitability when both IGSR and OGSR are of interest. The project studies GSR deposition in enclosed and open environments and evaluates secondary exposure risks during arrest protocols (task 2) and on shooters, bystanders, and passersby individuals (task 3). Finally, task 4 assesses the readiness of portable screening devices for future adoption through interlaboratory testing with an accredited forensic laboratory. This proposal's overall framework and interconnected objectives address several needs in the GSR field aligned with existing NIJ Strategic Plans, the NIST/OSAC GSR subcommittee, and the TSW. The project will create a much-needed set of criteria for law enforcement and forensic scientists that consolidates specific information on fundamental aspects of IGSR/OGSR evidence to advance the discipline. CA/NCF