Cutaneous wound metallic residues pattern analysis with SEM-EDX in a forensic case of overkill

Abstract

The term overkill identifies the infliction of massive injuries that greatly exceed those needed to kill the victim both in number and intensity. We present the case of a Peruvian transsexual, who was choked and hit by 11 sharp-force wounds all in the facial area. The scanning electron microscopy with energy dispersion X-ray analysis carried out on the skin of the facial wounds proved crucial in proving that two different point-and-edge weapons were used, following the finding of metallic micro-traces of heterogeneous composition. This discovery and the autopsy highlighted the use of two distinct types of injury (mechanical asphyxia and sharp-force trauma) showed that this murder amounted to overkill.