The use and understanding of forensic reports by judicial actors—The field of gunshot residue expertise as an example

Abstract

A comprehensive review was conducted on 42 closed court cases for which at least one gunshot residue (GSR) expertise had been requested. The aim of this study is to examine the use and understanding of the GSR findings by criminal justice professionals, the contribution to/relationship with other (forensic) elements of the case, and ultimately to assess the place of the GSR expertise in judicial decisions. The study shows that, in the vast majority of cases, the court appeared to interpret and use the GSR findings correctly, although some minor misuses were identified, mainly when the court incorrectly mentioned the expert's words, using the prosecutor's fallacy. In the end, a higher percentage of conviction rate (+23% points) was observed when incriminating GSR findings were obtained. Surprisingly, in half of the cases examined in which a guilty verdict was reached, GSR evidence was the only forensic evidence in the file.