Gunshot location through recorded sound: a preliminary report

Using a video tape and three still photographs, we analyze recorded sound to attribute authorship in a fatal shooting incident. We measure the acoustic signature of the scene with four test detonations, and we discuss two methods of processing putative echoes in the audio band of the video. They allow us to locate 11 out of 17 shots, with a precision of 0.4 x 1.0 m2. Combining the location of the shots with the known positions of the participants, we arrive at the clear attribution of eight shots; three other shots (among which is the fatal one) probably issue from the same shooter, who remains unidentified within a small group of men. Our results lead to the exculpation of the main suspect. We analyze the statistical significance of the results, use Monte Carlo simulations to set an upper bound to the probability of false positives, and discuss areas of improvement of the method.