Study of gunshot residues from Sintox® ammunition containing marking substances

:Two types of factory marked Sintox® ammunition were investigated from the composition of gunshot residue particles (GSR) and occurrence of marking substance points of view. The experiments were carried out with two cartridges of caliber 9 mm Luger (9 × 19 Parabellum) of two producers (Ruag Ammotec, Switzerland and Men, Germany). The first cartridge (type Action 4, Ruag Ammotec) contains gadolinium as a marking element, while the other cartridge (type PEP II, Men) is marked with gallium in gunpowder. Scanning electron microscopy equipped with EDAX analyzer (SEM/EDX) was used to detect and analyze the GSR particles in samples collected from the cartridges, barrels and shooter’s hands. Besides those, particles from the hit clothes placed at different shooting distances were collected and analyzed. The spreading of GSR cloud from the gun was observed using the high-speed camera. Results obtained clearly revealed that the way of ammunition production/construction and type of marking of ammunition can significantly influence the presence and detection reliability of marking elements in GSR. The detectability is affected also by the shooting distance.