Evaluation of morphological and chemical differences of gunshot residues in different ammunitions using SEM/EDS technique

Abstract

ABSTRACTIn this study, gunshot residues (GSR) of eight different original ammunitions were studied. Gunshot residues collected by the tape-lift method from both of the shooters' hands were analyzed using the SEM/EDS technique. Analysis was performed separately for each ammunition and each shooter using different firearms. Only the primary residues were taken into account for the analysis of the samples. The relationships between the chemical compositions and morphological structures of the ammunition types were investigated and classified. The mutual relations between the frequencies of occurrence of the morphological structures of different ammunition types were analyzed using nonparametric statistical methods (R-Spearman and τ-Kendall correlations). The elemental composition of GSR was found to be associated with the primer type. Different morphological classes, typically smaller than 100 μm in radius, were also identified. The percentages of frequencies of morphological classes of GSR obtained for different ammunition types were found to be similar. The ammunition type can be determined by comparing the primers from test shots with the primer composition obtained by the tape-lift method from a suspect's hand or firearm and cartridge. There is little in the literature about the environmental impacts of gunshot residues. Direct and indirect ingestion of GSRs, which lead to the poisoning of wildlife and the contamination of soil, needs to be evaluated carefully.