Is it possible to determine firearm calibre and shooting range from the examination of gunshot residue in close range gunshot wounds? An experimental study

Abstract

Introduction: The aim of the study was determining the type of weapon and shooting distance depending on chemical analysis of inorganic gunshot residue from the skin gunshot wounds in experimental animals (pigs).
Methods: Experimental study was conducted in order to determine components and their percentage in gunshot residue (GSR). In 60 samples, pig skin was shot by fi ring projectiles from four different weapons and from three different distances (contact wound and near contact wound from 5 cm and 10 cm). The methodology included determining the presence of inorganic material: antimony, barium, lead, nickel, zinc and copper in the skin and subcutaneous tissue using atomic absorption spectrophotometry (AAS).
Results: Formula for determining weapon type was provided cutt-off points for different weapons, with 78.6% of original grouped cases being correctly classifi ed. Formula for determining weapon type was provided cutt-off points for different distances, with 58.9% of original grouped cases being correctly classified, which was slightly less reliable compared to weapon type discrimination analysis.
Conclusion: The presented study showed that chemical analysis of GSR in entrance wound with AAS could be useful in determining the type of weapon, as well as the shooting distance, i.e. in our study, determining
whether the wound is contact or near contact. This could be particularly useful in postmortally putrefi ed or charred bodies with gunshot wounds.