Gunshot residues in fly puparia and soil around pig carcasses: A new perspective on forensic expertise

Circumstances that may be related to death in cases of skeletonized bodies pose a challenge for a forensic expert, as in this condition, the soft tissues that most readily reveal the determining factor for death are absent. However, it is essential to evaluate other traces surrounding a body. On the other hand, few studies have investigated gunshot residue in the soil and fly puparia associated with the corpse. The objective of this study was to evaluate the chemical elements released by gunshots in samples of dipteran puparia and the soil surrounding the carcasses for at least 120 days after death. Six pig carcasses exposed in an open environment were used for these evaluations; three were subjected to gunshot wounds, and three were not subjected to the treatment. Samples of fly puparia and soil beneath the carcasses were collected 50 and 120 days after the start of the experiment. The analyses were performed using Inductively Coupled Plasma Mass Spectrometry (ICP-MS). The results show that Pb and Ba levels in puparia and soil samples from carcasses that were shot were higher than in samples from carcasses that were not shot. The levels of these elements remained constant throughout the experiment in the puparia. The presence of higher quantities of these elements in the shot samples demonstrates the potential of these matrices as complementary sources of evidence in forensic investigations involving bodies in advanced stages of decomposition.