Application of luminescent markers to ammunition encoding in forensic routine using a Video Spectral Comparator (VSC)

Abstract

Gunshot residue (GSR) is an important part of forensic evidence. The implementation of non-toxic ammunition (NTA) hampers GSR characterization by conventional techniques. As an alternative, the incorporation of luminescent markers to ammunition has been proposed. The possibility of aggregation of different markers into gunpowder enables the possibility of ammunition encoding. Thus, the main objective of this study was to differentiate and evaluate for forensic use two previously studied ammunition markers based on europium ion (Eu(BTC) and Eu(BDC)) by employing a Video Spectral Comparator (VSC), well-known and widely used in scientific police laboratories. Chemometric methods demonstrated an unequivocal identification of the LGSR tested samples resulting in a 100% correct classification rating using Partial Least Squares Discriminant Analysis (PLS-DA).