Lead-Free Gunshot Residues as Forensic Evidence

<p>The analysis of gunshot residue (GSR) has been forensically relevant for many years and several methods are well characterized in scientific literature. However, the manufacture and distribution of lead-free alternatives to small caliber firearms ammunition is increasing rapidly as these types of rounds are more environmentally friendly and safer for use in indoor shooting ranges. Removing lead-containing compounds (e.g., lead styphnate) from the primer mixture eliminates a significant chemical marker vital to the legal precedent governing GSR analysis. The American Society for Testing and Materials (ASTM) standard ASTM E1588-95 is no longer applicable to such residues. With this emerging market, the forensic community must develop and validate methods aimed at the detection of lead-free GSR on the hands of suspected shooters. This study investigated the use of Laser-Induced Breakdown Spectroscopy (LIBS) and Scanning Electron Microscopy Energy-Dispersive X-ray Spectroscopy (SEM-EDX) as means of characterizing simulations of lead-free primers and GSR originating from the discharge of lead-free blank training rounds, typically used by law enforcement. As a result, forensic investigators will be provided with: a chemical profile for lead-free GSR using LIBS; the fully characterized rates of error associated with this method for shooters and non-shooters; and the lifetime that forensically relevant quantities of lead-free GSR can be recovered from the hands of a suspected shooter. Additionally, this study serves as the first recorded comparison in the analysis of lead-free GSR via LIBS as a rapid and relatively non-destructive screening method followed by confirmation with SEM-EDX on the preserved evidence.</p>

Name thesis:degree_name

Master of Science in Chemical Sciences (MSCB)

Level thesis:degree_level

Thesis

Discipline thesis:degree_discipline

Chemistry

Year dc:date.available

2016

Author dc:creator

• Fambro, Lashaundra A.

Contributors dc:contributor

• Dr. Christopher Dockery
• Dr. Michael Van Dyke
• Dr. Heather Abbott-Lyon

• lead-free
• gunshot residue
• laser-induced breakdown spectroscopy
• evidence preservation
• Analytical Chemistry

Repository record dc:identifier

https://digitalcommons.kennesaw.edu/mscs_etd/6

OAI identifier oai:identifier

oai:digitalcommons.kennesaw.edu:mscs_etd-1005