Comparison of cartridge case and airborne GSR—a study of the elemental composition and morphology by means of SEM‐EDX

Abstract

AbstractA comparative study of the properties of gunshot residue (GSR) collected from shooter's hands and from inside the case of the same cartridge used in a shooting experiment was performed. Three types of popular Luger 9 mm ammunition were chosen with primer mixtures based on different types of detonators: mercury fulminate, lead styphnate or lead azide and an organic one, e.g. diazodinitrophenol. Two modifications of lead‐free ammunition, with copper and tin plated projectiles were used. Samples of GSR were examined by means of scanning electron microscopy and energy dispersive X‐ray spectrometry. Both, similarities and differences in the chemical composition and morphology of GSR secured from the hands of the shooting person and from the appropriate cartridge case were observed. The chemical composition of the characteristic gunshot particles originating from the primer may be influenced by the chemical composition of other parts of the cartridge case, especially the core and the jacket of the projectile. Thus, the distribution of the chemical elements in GSR strongly depends on the direction of the reaction path starting in the primer cup placed at the bottom of the cartridge case, moving along the cartridge case and finishing when the projectile leaves the gun muzzle. A reliable comparison of the airborne residue to these taken from cartridge case for forensic purposes requires some experience based on laboratory experiments performed under controlled conditions. Copyright © 2007 John Wiley & Sons, Ltd.