Detection of fragments of an obstacle and a projectile in a gunshot injury

BACKGROUND: Law enforcement agencies look for the presence of an obstacle between the human body and the muzzle of a firearm at the time of the shot when assigning forensic medical examination of a firearm injury. Imported particles removed from the corpse, a skin flap, or damaged clothing could be sent for a laboratory examination.

CASE PRESENTATION: Here, we present a case from expert practice which demonstrates the possibility of establishing the presence of barrier particles on surrounding objects in the case of a gunshot injury caused to a person. In the given case, detecting the fragments of an obstacle (triplex ― the windshield of a car) played a leading role in proving the suspect’s involvement in the incident under investigation. Described are the violations of an expert method of particle removal (in one case only, the material obtained from the clothing was placed on a special carbonic adhesive tape during a targeted search of micro overlays) and evaluation of the obtained data which contributed to incorrect findings in the expert’s conclusion.

Experts of the Federal State-Owned Institution “111 Main State Center for Medical and Forensic Examinations” conducted a re-examination of the above-stated objects, as well as experimental target shooting with similar weapons through a similar barrier. Presented are the possibilities of modern scanning electron microscopy and energy dispersion analysis, which allow not only to establish the presence of barrier particles on surrounding objects but also to identify the signs of gunshot damage inflicted upon a human body and clothing, identify the destroyed projectile particles, and establish the elemental composition of all the detected microparticles.

CONCLUSION: This study demonstrated the methodological gaps in establishing the existence of a passage of a firearm projectile through an obstacle in the case of a gunshot injury. The methods for identifying the fragments of a firearm projectile and particles of an obstacle, which we are currently developing, are aimed at solving this problem by improving the corresponding research methods in forensic medicine and science.