Miscellaneous Objects

Barbecue forks with two or three prongs can cause sharp injuries, that can be identified as groups of two or three wounds, with regular or irregular distances between the wounds caused by each prong depending on the angle and force of the stabbing (Spitz, 1993; Di Maio & Di Maio, 2001). Broken glass produces incised wounds with jagged and sharp edges. In cases of multiple wounds, they may exhibit distinctive shapes, depths, and sizes. In these cases, the wounds should be inspected for glass fragments (Spitz, 1993; Di Maio & Di Maio, 2001).

Hunting activities that utilize arrows and crossbow bolts may produce sharp force wounds. However, even domestic animals may suffer penetrating wounds from arrows or other nonidentified sharp objects, as revealed in a study of cats (De Siqueira et aL, 2012). Wounds will vary from circular to X-shaped lesions and in varying sizes and shapes. Because of the force used to produce them, wounds may have bony fractures, hemorrhage, and damage to internal organs. They may be difficult to differentiate from bullet wounds. The track of the wound may assist with differentiation, because a bullet may leave an abrasion ring and an arrow will slice the underlying tissue and may cut a line in the adjacent hair. In both cases, radiographic examination is crucial. Bullets may leave lead pathway or fragments that may reach the bone, and other sharp objects may leave metal fragments only seen by radiographic examination. Ice picks may cause lesions that mimic shotgun pellets because they result in small, slit-shaped or round wounds (Spitz, 1993; Di Maio & Di Maio, 2001).

The veterinary pathologist may be summoned as an expert witness (Frederickson, 2016), and may be asked about positioning, type of object/weapon, and force utilized by the perpetrator. Biomechanical factors to consider include the properties of the knife (weight, shape, and sharpness), velocity and type of thrust and the movement of the knife within the body, skin and organ resistance (viscera, bone), movement of the victim, movement of the knife from the skin to its termination within the body, and the speed and direction of delivery of the blow (Knight, 1975; Annaidh et al., 2012). However, the exact quantification offerees can be difficult to determine, even with all these elements present.

Identifying and Examining Sharp Trauma Lesions

The identification and examination of sharp trauma lesions requires a protocol, as depicted in Figure 8.3.

Considering all types of sharp injuries that may be encountered in a criminal investigation, the following procedures are recommended (Byard et aL, 2006; Cooper & Cooper, 2008; Merck, 2012; Salvagni et al., 2014; Brownlie and Munro, 2016):

1. Radiographic examination: Before performing the necropsy in cases of suspicious death, radiographic examination will aid in discovering bone fractures and/or blade fragments. Another use is to differentiate tool marks, which may indicate the type of weapon used to produce the stab wound.
2. Inspection of fur/feathers and skin: Sharp lesions in humans are readily seen and are obvious. This is not always the case in animals, due to hair coat or feathers, pigmentation of the skin, and unique characteristics of the skin depending on the species. A careful external examination should be performed to look for crusted or dry blood. The wound should

be palpated. In cases of multiple wounds, they should be individually numbered and documented using a diagram of the animal body and indicating the anatomical location.

3. Photographic documentation: Photograph the animal with and without identification. As each wound is found, photograph it with a scale and animal identification before and after washing with water and shaving. Whenever possible, compare the photographs with those taken at the crime scene. In some cases, the morphology of the wound may be changed by the movement of the carcass or due to postmortem phenomena. Modifications of the positioning of the carcass, in addition to postmortem phenomena, may modify the shape of the lesions, leading to misinterpretations. Thus, it is recommended that photographs should be taken both at the crime scene and in the necropsy room. These photographs should be compared, and differences should be noted and analyzed.

1. Perform an accurate external examination (skin and mucosa)
2. Examine the skin wound by measuring it and localizing it
3. Photograph the skin wound^[1]

Mucosa may present whitish discoloration due to blood loss in internal organs Dry blood on the fur may indicate blood loss on that anatomical region

• Identify the animal (name, species, gender, age, date of the necropsy/dinical examination)
• Take pictures from the animal and the wound(s), to determine it
(their) position and anatomical location
• Identify wounds individually
4. Perform necropsy/clinical examination
•Take photographs before and after cleaning the wound with water

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• Write a detailed report with all necropsy/dinical examination findings, adding ancillary exams, such as x-ray and blood count, if it is the case

Figure 8.3 Stepwise flowchart for the examination of sharp force injury.

4. Accurate description of lesions: This should include marks around the wound, color, edges, and shape. Reflect the skin to reveal and document possible lesions in subcutaneous tissue. The shape of the lesion may be affected by the sharpness of the instrument, the movement of the victim, the force of the thrust and the underlying tissue (bone, cartilage, soft tissue, viscera). A typical sharp force wound may occur when the victim moves or the knife twists. In such cases, lesions may present a V-shaped pattern that is produced by a slight movement of the victim or the knife, and/or a Y- or L-shaped pattern that can be produced by a secondary path produced by the removal of the knife.
5. Obtain an estimation of blade width and length: To obtain an estimation of blade width and length, reconnect and measure the edges of the lesion. The length of the stab wound is equal to or greater than the width of the blade. In cases of multiple lesions, each one should be measured, and the average measurement may give an estimate of the blade width and length. Consider the contraction of the skin due to its elasticity. Other consideration should be given to the cleavage or Langer’s lines. They are patterns of collagen and elastic fibers that produce elasticity to the skin, and the shape of the wound should be correlated to the angle formed with these lines. It should be noted that a particular knife can be ruled out, but not conclusively ruled in without metal fragments matching it from a wound.

■ Stab parallel to Langer’s lines: A narrow slit-like wound is produced.

■ Stab perpendicular to Langer’s lines: These fibers pull the edges of the wound apart, creating a gaping wound.

■ Stab oblique to Langer’s line may produce an asymmetrical or semicircular patten depending on the fibers.

6. Trace the track of the stab: Examine underlying tissue and viscera that may be affected in deeper wounds due to the force and the angle of the thrust.
7. Histopathological analysis: Collect fragments of both sides of the wound to look for evidence of hemorrhage. Chop wounds and stab wounds made with dull objects, or with uneven edges should be differentiated from blunt force trauma lesions. In cases that involve bone and cartilage, the detailed and accurate observation of the specimens may help to find marks of sharp objects, which may lead to their identification.

[1] • If possible, before the examination, utilize x-ray exam to study lesions and possible metal pieces left by sharp instruments 2 Utilize external injuries as a guide to examine viscera/blood vessels that may be affected by sharp injuries