Glass-containing gunshot residues and particles of industrial and occupational origins: Considerations for evaluating GSR traces

Abstract

In an ideal case, the value of traces would be determined numerically and presented through the use of likelihood ratios or verbal-equivalent scales. A problem in the evaluation of gunshot residue (GSR) evidence using these models is that in many shooting scenarios insufficient data exist to support a quantitative model of interpretation. The complex relationship that exists between ammunition composition and post-firing residues makes quantitative interpretation more difficult for GSR than for other traces such as glass. When evaluating the significance of traces in a quantitative model, the value of a trace is reduced as the number of random sources that could produce the trace increases. ..