External Examination
The external examination is perhaps the most critical and time-consuming aspect of the forensic autopsy. In order to evaluate the autopsy findings in context and form professional interpretations, the veterinary examiner should ideally review the circumstances of death or clinical history prior to initiating this portion of the examination. If not already done, all surfaces of the body should be photographed as submitted without any cleaning or other alteration. Special attention and documentation should be given to areas in which wounds, medical or surgical intervention, or other abnormal findings are identified. If any relevant foreign materials are present that may be considered as trace evidence, these should be collected and documented.
The examiner should record the body measurements including weight, crown—rump length, overall nose—tail length, chest girth, and shoulder height. The examiner should record the sex and neuter status as well as the apparent age. The nutritional condition of the animal should be described, preferably in accordance with an accepted species-specific body condition scoring system if one exists. It is prudent to specify the scale used by both name and by the range of possible scores so as to avoid uncertainty in interpretation. The veterinary examiner should then describe the state of hygiene and grooming using a standardized scale or descriptive objective language to characterize the condition and cleanliness of the hair coat, nails, ears, and teeth, and the presence or absence of any external parasites. Any dental anomalies, such as broken, loose, or missing teeth, should be noted using a standard species-specific dental chart.
Consideration should be given to the removal of nails or claws if they may contain trace evidence to be preserved. In this case, the keratin portion of the claw in its entirety can be severed with a sharp instrument and preserved in a paper evidence bag or envelope. Alternate light sources may assist with the evaluation the carcass and packaging materials when searching for trace evidence. After the initial external examination and collection of evidence, the body may be washed if necessary, to permit more complete evaluation, and then further examined and photographed.
When the examination of the superficial external body surfaces is complete, the examiner must consider the most appropriate strategy for evaluating the skin surface beneath the hair coat or feathers. Depending on the condition of the hair or feathers it may be preferable to clip the hair or pull the feathers to expose the skin surface. This may not be possible if the hair coat is wet or severely matted or if decomposition is advanced. In the case of wet or matted hair, it may be necessary to limit the clipping of hair to small suspect areas, to shave the hair over suspect areas using a razor or scalpel,
Figure 10.2 Samples to be collected to establish the identity of the body. Samples should minimally include swabs of the oral mucosa and hair with intact roots.
or to forgo the examination of the external skin surface and instead rely on the subcutaneous exam as described in the next section. In the case of advanced decomposition resulting in skin sloughing, the mechanical removal of the epidermis is often easily achieved by gentle hydraulic pressure from a water hose. This method results in diffuse removal of the epidermis from the body surface and loss of superficial detail, but changes to the subjacent dermis are made clearly visible.
The examiner should describe the state of postmortem preservation, documenting any postmortem changes including lividity, rigor, decomposition, and insect development (Brooks & Sutton, 2018). If appropriate, the body temperature should also be measured and recorded with notation of the site at which the temperature was measured, and the temperature range of
Figure 10.3 Photograph of gunshot wound on the skin of a cow. Note the camera angle is perpendicular to the surface of the skin and the scale is in the same plane of focus as the lesion.
the thermometer used. Many clinical thermometers do not record below 35°C (95°F), however hypothermia thermometers will read to much lower temperatures, thus a reading below the limit of the thermometer must be further defined.
To complete the external examination, any external wounds or injuries should be thoroughly described noting the injury type, location, size, shape, and pattern; such lesions should be photographed with a scale (Figure 10.3). Similarly, any evidence of medical or surgical intervention should be documented. All body orifices should be evaluated for exudate, hemorrhage, or foreign materials; special attention should be paid to the genitalia and anus for indication of sexual abuse. All extremities such as limbs, wings, and tail, must be palpated or otherwise examined for indication of internal injuries such as crepitus, deformity, etc. Any abnormalities detected on external examination should be photographed and should be documented on a pictorial diagram to indicate the location on the body using measurements from major body landmarks (Figure 10.4).
