Scanning Electron Microscope Analysis of Gunshot Defects to Bone: An Underutilized Source of Information on Ballistic Trauma

Abstract

Recent years have seen increasing involvement by forensic anthropologists in the interpretation of skeletal trauma. With regard to ballistic injuries, there is now a large literature detailing gross features of such trauma; however, less attention has been given to microscopic characteristics. This article presents analysis of experimentally induced gunshot trauma in animal bone (Bos taurus scapulae) using full metal jacket (FMJ), soft point (SP), and captive bolt projectiles. The results were examined using scanning electron microscopy (SEM). Additional analysis was conducted on a purported parietal gunshot lesion in a human cranial specimen. A range of features was observed in these samples suggesting that fibrolamellar bone response to projectile impact is analogous to that observed in synthetic composite laminates. The results indicate that direction of bullet travel can be discerned microscopically even when it is ambiguous on gross examination. It was also possible to distinguish SP from FMJ lesions. SEM analysis is therefore recommended as a previously underexploited tool in the analysis of ballistic trauma.

Bullet Caliber and Type Categorization from Gunshot Wounds inSus Scrofa(Linnaeus) Long Bone

“…A forensic anthropologist or pathologist would be able to look at the size of the entrance wound, the presence of lead on the margins of the wound, and the presence or absence of cortical flaking to approach the question of the size and type of bullet used to inflict that wound. We are in agreement with the conclusion that SEM analysis is underutilized in the analysis of ballistic trauma (28). This research lends itself to the now more focused description of ammunition used during the search and seizure of evidence.…”

“…Therefore, the presence of cortical flaking is associated with trauma on bone from a copper bullet, while the absence of flaking is indicative of a bullet made of lead. The characteristics of bullet wound morphology from full metal jacket bullets are supported by Rickman and Smith's research .…”

Fantastic plastic? Experimental evaluation of polyurethane bone substitutes as proxies for human bone in trauma simulations

“…The work detailed in the current paper is part of a wider suite of ballistic experiments with relevance to Forensic Anthropology. One of these parallel projects [6] utilized cattle (Bos taurus) scapulae as proxies for human cranial bone in considering microscopic effects of gunshot trauma. Here fresh scapulae obtained from an abattoir from animals that had been slaughtered for food, were shot with minimal soft tissue (<5mm thick) adhering.…”

“…Further, the microstructure of bone has been shown to influence its response to ballistic trauma in complex ways at a microscopic level, including delamination, directional cortical bending and lateral deflection of portions of cortex. It has been demonstrated that such changes are recognizable to the extent that they can be used to differentiate between different types of ammunition microscopically [6]. In contrast to this organized complexity, polyurethane has an essentially uniform microstructure devoid of regular organization above the molecular level.…”

Interpersonal violence among the Chalcolithic and Bronze Ages inhabitants living on the Central Plateau of Iran: A voice from Tepe Hissar

“…Weapons with a high velocity can also produce extensive fractures. The nature of this type of injury implies lethal intent (Lambert, 1997:90;Rickman and Smith, 2014).…”