Preliminary Imaging Techniques
Radiographic examination of the body is an invaluable tool for the postmortem assessment of orthopedic injuries and identification of foreign bodies and projectiles (Gerdin & McDonough, 2013). Radiographs are encouraged for all forensic cases; however, they should be considered compulsory for cases in which the body is incinerated or if skeletal injury, foreign body, or projectile injury is suspected.
If radiographic imaging is performed, it should be done prior to examination of the body. Specifically, radiography is ideally performed as the first stage of the examination, prior to removal of the body from any packaging in which it was submitted (Figure 10.1). If this is not possible or reasonable, radiography may be delayed until after external examination but prior to internal examination. Attempting radiography after the body has been opened will almost certainly create artifacts, precluding evaluation of some features. This technique should only be used if pre-necropsy radiography was not possible. Radiographic examination is frequently declined by the submitter due
Figure 10.1 Radiograph of a dog submitted within two layers of plastic bags. Positioning and reduction of artifacts from bagging material can present a challenge, but good quality images can be obtained.
to cost. If declined, this should be documented in the case record, preferably with the signature of the submitter. A radiography release form, explaining the costs and benefits of pre-necropsy radiography, may aid the examiner in obtaining permission or documenting refusal.
Radiographs should consist of two orthogonal views of each body region, and all body regions should be imaged. All radiographs should include the date, case number, clinic or laboratory name, animal ID, and positional markers.
Establishing the Identity of the Body
The examination of the body begins with a thorough description of the evidence as submitted with emphasis on the external characteristics of the body so as to establish the identity of the victim. The examiner should record, either by written or dictated record, all examination findings. By using a standardized form, the examiner can ensure that all aspects of the examination are completed and there is no omission. Additionally, a photo log may be used to record a description of each photograph taken if resources permit. An initial photo should be taken of a laboratory or clinical document that contains identifying information such as the case number, animal or submitter name, and exam date. This is useful in establishing the identity of all subsequent photographs.
Documentation of identity should begin with a description of the manner in which the animal was received by the submitter. This should state, for example, whether the animal was delivered by the submitter or shipped by a courier. The description should further describe the packaging materials and cooling devices used, if any, to contain and preserve the body. These items should be sequentially photographed throughout the unpacking and unwrapping process; the packing materials should then be properly preserved. The examiner then photographs the carcass including case numbers in the photos. All surfaces of the body should be photographed as originally submitted, and additional emphasis should be placed on any identifying features such as unique markings,
Techniques tattoos, or identification tags (Kagan & Brooks, 2018). These photos will also serve to document general features for the confirmation of animal species and breed, including color and length of hair coat or feathers. Documentation of sex and body measurements are critical to the identity of the animal and will be described in the next section. The examiner scans the carcass for the presence of an implanted microchip. Prior to scanning it is advised to run a positive control using a known microchip to confirm the proper functioning of the scanner. If a chip is detected, the information (such as microchip number and/or manufacturer) displayed by the scanner should be recorded; if no chip is detected, this should be recorded. The scanner result should be photographed.
Following this written description and photographic documentation of the identifying features of the victim, the veterinary examiner is then compelled to collect and properly preserve any items that will serve to maintain the identity of the animal. Such items may include identification tags or devices found on the body as well as biologic samples for DNA analysis. Each item collected is recorded in a written evidence log. Samples to be collected for DNA include hair (preferably with intact roots), buccal mucosal swabs, and scrapings of dried fluids. Hair samples should be stored in paper or glassine evidence envelopes, while wet fluids should be swabbed, allowed to dry in a drying rack, and placed in a swab holder box or paper envelope (Figure 10.2). Dry fluids may be swabbed with a moistened swab and then stored as previously described for wet fluid swabs. Any other tissue samples should be frozen at -20°C to -80°C.
