How Decomposition and Processing Affect Metallic Particles From a Bullet in Gunshot Defects

A significant portion of forensic anthropological cases involve decomposed or fragmented human skeletal remains. When testifying in a courtroom, often the focus is on trauma interpretation and distinguishing between blunt force trauma, sharp force trauma, or high-velocity projectile trauma. Therefore, forensic anthropologists need to understand how various factors and processes alter human remains during the decomposition process and how those changes affect the interpretation of skeletal trauma patterns. The primary research question addressed in this study is: how does the decomposition and processing of human remains impact the preservation of metallic fragments from gunshot trauma? Fifteen hog (Sus scrofa) crania were shot using hollow-point and full-metal jacketed 9mm ammunition with an 8-foot firing distance. Eight skinless slabs of hog ribs were shot using the same ammunition types as the crania. All hog samples decomposed in an outdoor environment under metal cages to prevent scavenging. Radiographs were taken of each hog sample before and after decomposition and after processing. The results show metallic fragments from the bullet embedding in the soft tissue more frequently than in the hard tissue. Scavengers, mummification, and processing are three critical factors that were found to influence the removal/preservation of metallic fragments during the decomposition process.