Weapon-wound matching of sharp force trauma to bone – a micro-CT analysis

Abstract

Nearly 40% of murders in the UK result from sharp force trauma caused by knives. Weapon-wound matching in Forensic anthropology attempts to estimate weapon class from the wound characteristics but few studies have investigated quantitative methods for performing this analysis on the microscopic scale. In this study five cadaveric pig torsos, prepared to mimic human anatomy, were stabbed in the upright position with 12 different knives. Knife dynamics were recorded using a Casio high-speed camera (420fps). Samples were chemically defleshed exposing the regions on the ribs where the knives have made contact, thus marking the bone, so micro-CT can be performed. All samples underwent a pre and post-stab CT scan so that rib marks could be matched to the knife used. Preliminary results show that there is a significant difference between serrated and none serrated cut geometry regardless of knife force or penetration angle. If these results hold true for the larger sample of knives tested within this study (analysis currently in progress) and the significant differences between knives are above noise then, a new technique for statistically estimating knife class from cut marks can be developed. Applications of this in forensic anthropology will aid criminal investigators in their inquiries