DNA analysis of biological material on perforating bullets and crime scene reconstruction

Abstract

DNA analysis of biological material present on a bullet surface may be an important tool for the reconstruction of a crime scene. In shooting incidents when there is more than one gunshot or victim or when the crime scene has been changed, the presence of DNA on the implicated bullet may determine that it hit the victim. The comparison of this bullet and the firearm(s) involved may identify the gun from which the bullet was fired and help to define the shooter. We report two cases of homicide by firearms in which biological material was recovered by swabbing the bullets. DNA was extracted and PCR typing of STR was carried out using the AmpFLSTR ® Identifiler (Applied Biosystems). In both cases we obtained genetic profiles from different regions on the surfaces of the two projectiles. In the two situations, DNA typing played a decisive role in the reconstruction of the crime scenes.