Detection of gunshot residues in routine CTs

The forensic assessment of non-fatal gunshot wounds often proves to be difficult as wounds have usually been cleaned and protected with a sterile bandage by the time of the examination. The aim of our investigation was to test the possible application of computed tomography (CT) for the forensic assessment. Doing so raised the questions whether gunshot residues in the soft tissues, detected by means of 3-dimensional CT, can be used as evidence of a close-range shot and whether conclusions can be drawn pertaining to the range of the shot or the type of bullet used based on the distribution of the radiologically detectable material? In this experimental study 39 shots were fired at fresh pig skin and it was possible to distinguish shots fired from distances of more than 10 cm and contact shots independent of the type of bullet. For unjacketed lead bullets, radiopaque material could be seen in the depth of the entrance wound for firing distances up to 10 cm. In individual cases, CT data and the 3-D reconstruction could provide valuable information in the forensic assessment of patients with gunshot wounds.