Cruel traces: Bone surface modifications and their relevance to forensic science

Abstract

The reconstruction of perimortem and postmortem events is of critical importance to criminal investigations. In many cases, the information required for these reconstructions can be accessed through the analysis of skeletal remains. One particular class of skeletal data—trauma to the surfaces of bones, or bone surface modifications (BSMs)—can reveal much about the perimortem and postmortem intervals. While the study of BSMs originated within the fields of paleontology and archeology and was only later integrated into forensic science, a fruitful interdisciplinary exchange of data and methods is now commonplace. BSMs from thermal alteration, sharp‐force trauma, terrestrial and aquatic scavengers and predators, bacteria and fungi, insects, weathering, and sediment abrasion can supply investigators with valuable information about the agents and events of a corpse's deposition, including weapon type, local environmental conditions, the postmortem interval, and the presence, temperature(s), and/or length(s) of thermal exposure. Based on a review of this rich body of literature, we argue that (a) all associations between a BSM and its alleged source must rest on observational cause‐and‐effect studies; (b) secure identifications of BSMs should rely both on the intrinsic features of the modifications themselves and relevant contextual data; (c) the scientific validity of BSM research depends, ultimately, on rigorous blind‐testing and the establishment of error rates; and (d) researchers need to make a concerted effort to enhance interanalyst correspondence through objective definitions, measurements, and/or codes of BSM features. The most promising path forward lies in the combination of digital image analysis and multivariate predictive modeling. This article is categorized under: Forensic Anthropology > Trauma Analysis Forensic Anthropology > Taphonomic Changes and the Environment Forensic Anthropology > Time Since Death Estimation

Identifying Blunt Force Traumatic Injury on Thermally Altered Remains: A Pilot Study Using Sus scrofa

“…Per contra, when a bone is exposed to rapid force, such as is seen with gunshot trauma, it will react as a more brittle material and fracture with little to no associated plastic deformation [ 6 , 7 , 8 , 13 , 14 , 15 , 16 ]. This brittle reaction is also characteristic of postmortem dry bone breakage [ 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 ]. Both plastic deformation and complete bone failure leave distinct signatures on the bone when observed both macro- and microscopically [ 6 , 7 , 8 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 ].…”

“…This brittle reaction is also characteristic of postmortem dry bone breakage [ 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 ]. Both plastic deformation and complete bone failure leave distinct signatures on the bone when observed both macro- and microscopically [ 6 , 7 , 8 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 ]. There is general agreement that if the biomechanics of bone’s reaction to force remain as a constant variable, then interpreting the timing of traumatic injury should be possible despite postmortem taphonomic events and alterations [ 6 , 7 , 8 , 17 , 18 , 19 , 20 , 21 , 22 , 23 ].…”

“…Although the structural reactions of traumatized bone are well understood, post-depositional events can complicate interpretation. Taphonomic processes can introduce secondary fractures, alter fracture margins, or conceal impact sites [ 6 , 24 , 25 , 26 ]. Due to this, trauma signatures are addressed in variable depositional environments [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 ] to identify criteria that can be informative for trauma identification in specific contexts.…”

“…Taphonomic processes can introduce secondary fractures, alter fracture margins, or conceal impact sites [ 6 , 24 , 25 , 26 ]. Due to this, trauma signatures are addressed in variable depositional environments [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 ] to identify criteria that can be informative for trauma identification in specific contexts. However, few studies have addressed the influence of thermal alteration on blunt force trauma, specifically on the cranium.…”

“…However, few studies have addressed the influence of thermal alteration on blunt force trauma, specifically on the cranium. In forensic contexts, it is not uncommon for decedents to be disposed of by means of fire, as perpetrators of a crime often correlate the idea of a quick coverup with burning the body until only ash remains [ 20 , 21 , 24 , 25 , 26 , 27 , 28 ]. However, bodies exposed to fire burn slowly and are often recovered with intact skeletal or fleshed elements remaining [ 21 , 24 , 25 , 26 , 27 , 28 ].…”