Sharp Force Trauma

Introduction

Sharp force trauma consists of lesions caused by sharp objects, such as knives, scissors, screwdrivers, needles, or machetes (Pounder, 2000; Humphrey & Hutchinson, 2001; Bury et al., 2012; Parmar et al., 2012), and each object may leave a unique mark on the skin that may lead to their identification. In some cases, lesions caused by sharp objects may be misinterpreted as blunt force lesions, thus a histopathological analysis may be helpful to differentiate them (Ressel et al., 2016). Postmortem identification of lesions is crucial to the investigation of possible crimes against animals. For this purpose, veterinary pathologists play an important role by identifying the nature of the lesions, describing, measuring, and photographing them, giving a clue of the type of objects that might have caused them (Gerdin & McDonough, 2013; Salvagni et al., 2014). Wound patterns, such as position, shape, depth, and path may provide a lead as to whether the act that provoked them was intentional or accidental (Knight, 1975; Dettmeyer et al., 2014)—in this case, this information should be analyzed together with other crime scene findings, such as bloodstain pattern analysis (Attinger et al., 2013).

Lesions are not always easily identified in animals due to their physical aspects, such as the covering of hair and/or the color and the depth of their skin (Campbell-Malone et al., 2008; Munro & Munro, 2008; Merck, 2012). Thus, dry blood on the fur/feather and/or skin may indicate an underlying sharp lesion. Postmortem interval, the action of microorganisms and local entomofauna (Brundage & Byrd, 2016), environmental aspects, and crime scene elements (e.g., weather—humidity, dryness, or other climate conditions, or the place where the carcass was found—lake, river, indoor or outdoor) may interfere with the actual morphology of the lesions (Byard et al., 2005). Sharp lesions may or may not be lethal. Therefore, the necropsy may clarify the cause with the complete external and internal examination, which may give cause, manner, and mechanism of death.

Animals may present with sharp injuries that result from a variety of causes, such as social violence. They are considered as family members and they may be victimized by abusive acts as well as hunting, traffic accidents, or those involving vessels in the case of marine animals, therapeutic procedures, and religious practices (Arkow, 1994; Ascione et al., 2007; Aquila et al., 2014; Melo et al., 2014).

Defining Sharp Trauma Lesions and Sharp Objects

Sharp trauma lesions can be divided into four categories: (1) stab wounds, (2) incised wounds, (3) chop wounds, and (4) therapeutic/diagnostic wounds (Jones et al., 1994; Di Maio & Di Maio, 2001; Hainsworth et al., 2008; Dettmeyer et al., 2014). In some cases, it is important to hypothesize the positioning between the perpetrator and the victim, and the type of sharp object that caused the lesion (Spitz, 1993). Some characteristics of sharp objects and the stabbed area may provide some leads about it. Table 8.1 depicts their definitions and corresponding sharp objects.