Colourimetric based detection of gunshot residue on gloves worn during shooting

Abstract

Determining the shooter is an important element during investigation of firearm related offences, particularly through the detection of gunshot residue (GSR) as forensic evidence on shooter’s hand. However, such detection could be restrained if it is obstructed by the wearing of gloves by a shooter. Hence, it is worth investigating the presence of GSR on gloves, aiming to suggest an individual’s contact with a weapon. In this study, Modified Griess Reagent (MGT) commonly available in forensic laboratory was utilised to screen GSR on individual gloves of different materials worn by a shooter during a shooting training session. The experimental results revealed that both the palm and back of gloves equally allows the detection of GSR by MGT (p = 0.083). No statistically significant association was evident between the types of gloves and positive indication of MGT (p = 0.122). The types of firearms, neither revolver nor semi-automatic pistol showed significant association with the detection of GSR on the gloves (p = 0.248). When two-hand shooting was performed, glove samples worn on left and right hands gave almost similar testing results (p = 0.626). Although the presence of GSR on a glove after a shooting could be relatively low, the study has demonstrated that applying MGT, a simple test could assist crime scene investigation in determining the presence of GSR, in cases when gloves were used.