Controversial Suicide Case Using a Submachine Gun with a Sound Suppressor—The Need of Team Work of Forensic Chemistry and Firearm Examiners

Abstract

Evidence materials in a presumed suicide case were studied by a firearm examiner and a forensic chemist. The victim's body with double gunshot wounding in his forehead, a machine gun in the sustained fire mode with a silencer, and four cartridge cases were found. Examinations of the evidence, the case file studies, and experiments dedicated to the case were carried out. Relationships between the placement of cartridge cases and the gun were established using a fast camera. The distributions of gunshot residues on the evidence materials and within the comparative gunshot patterns were studied by means of optical and electron microscopy, X-ray microanalysis, and infrared spectroscopy. The shooting distance was assessed to be 30 cm or more, whereas the greatest distance that could have been achieved by the victim himself was about 11-13 cm. The obtained results supported the version of homicide rather than suicide.

Effects of the interaction of gunshot residue plume and cotton fabrics—an empirical study towards extensive assessment of close-range shooting distance

“…These detailed examinations of the array of shooting patterns depending on the shooting distance in the range of 0–30 cm, being included in the category of close-range distance, 27 were performed to be able to compare the GSR distribution with other similarly performed examinations, however, for different kinds of ammunition. The common property of GSR distribution obtained in the current study with these published earlier both for small arms 10,15,20,28 and also for a cal. 12 23 rifle was the relatively great amount of lead particles that most probably originated mainly from the lead core of the projectile and a smaller amount from the primer components.…”

“…26 However, the application of a 5 cm radius provides meaningful results for the analysis of various properties of GSR depending on the shooting distance. 10,15,20…”

“…Criminal cases, in general, and shooting incidents in particular, demand detailed examinations of the clothing items of the partakers as they usually provide important evidence. 11–15 Clothing is produced mainly of woven and knitted fabrics. Woven fabrics are made by using two or more sets of yarns interlaced at right angles to each other.…”

Toward Locard’s Exchange Principle: Recent Developments in Forensic Trace Evidence Analysis

“…Finally, studies modeled on real-life cases emphasize the relevance of GSR for forensic investigators. Brożek-Mucha and Zdeb conducted a study regarding a purported suicide case in which the weapon was a machine gun . The GSR in this case was studied using a variety of techniques.…”

“…Brozėk-Mucha and Zdeb conducted a study regarding a purported suicide case in which the weapon was a machine gun. 166 The GSR in this case was studied using a variety of techniques. Overall, researchers found that, on the basis of the evidence, including the GSR distribution, the case appeared to be more likely a homicide than a suicide.…”