Documentation and Collection of Evidence

This step can be time consuming and tedious, but mistakes made in this step can severely impact the progression and prosecution of the case. According to Lee et al. (2007), physical evidence is best described as “any evidence that can provide useful information for investigators in solving cases.” This description leaves the field wide open.

Physical evidence, in general terms, is any tangible object that relates to a crime or that can assist in establishing that a crime occurred. Physical evidence can also be an item that links a crime to its victim or suspect. Evidence adds information to the case. Evidence can provide facts of the case, including the timeline, demonstrate links between the elements of the crime, such as the scene, the victim, potential suspects, and items used during or relevant to the crime, substantiating or refuting witness accounts, elucidating the role of other evidence, identifying unknown items or substances, and reconstructing the crime and the crime scene (Gianelli, 2009; Fish et al., 2011; Fitch, 2015).

For animal cases, in the author’s experience, three general types of physical evidence are typically documented and collected: stable, biological, and live. Each of these types of evidence can require specialized handling. Obviously, stable evidence usually requires the least amount of initial processing. These objects, depending on the size, are often collected into evidence bags, sealed with evidence tape, signed by the collector, and secured in an evidence lockup area prior to any appropriate testing. The evidence tape and signature should be oriented so that opening of the package is easily visible. The package should be labeled with all information required by the agency in charge of evidence collection. This information may include case number, item number, agency, brief description, date and time of collection, and identification of the person collecting the evidence. It is often easier to label the container prior to packaging the evidence (U.S. Department of Justice, 2013).

Some additional general guidelines for the collection and storage of evidence include:

• 1. Fragile evidence or evidence that would be lost easily lost should be packaged first. Rigid cardboard containers can be used to prevent crushing of the evidence.
• 2. Evidence is usually placed in paper evidence bags, as plastic bags may be conducive to moisture condensation and mold growth.
• 3. If there is not sufficient time to allow wet items to air-dry while on scene, wet evidence can be temporarily packaged. As soon as the evidence has been moved to a secure area, the package can be opened and the evidence allowed to dry and then be repackaged. This evidence handling, opening, and resealing of the evidence packages should occur as soon as possible to minimize any deterioration due to the moisture. In addition, the handling procedures should be fully documented to maintain the chain of custody.
• 4. Liquid evidence can be collected and stored in vials with proper lids.
• 5. Small items of trace evidence, such as hairs or powder, can be collected into envelopes (manila or glassine) or contained in a druggist-folded paper.
• 6. In most circumstances, each piece of evidence is collected and packaged individually (Fish et al., 2011; Fitch, 2015; Merck, 2013).

Biological evidence is evidence that comes from a human or animal body. Examples include bodily fluids such as blood, semen, saliva, and other bodily secretions. Skin cells, hair, and hair follicles are also biological evidence but are not often collected as stains or smears. Proper collection techniques for biological evidence are essential to avoid the natural degradation that occurs with time and exposure to the environment (Merck, 2013; U.S. Department of Justice, 2013; Fitch, 2015).

Collection techniques for biological evidence commonly used are sterile (moistened with sterile or distilled water if the stain is dry) cotton swabs or gauze to collect the stain, or a sterile tool such as a scalpel or razor blade to scrape up the material (Fish et al., 2011; Merck, 2013; U.S. Department of Justice, 2013). One of the most inclusive techniques to collect and preserve biological evidence is to collect the entire material where the evidence is found. This can be done by cutting out the relevant section of material. Consideration should also be given to collection of control samples of materials not stained by the biological evidence (Merck, 2013; U.S. Department of Justice, 2013). If the biological samples are wet, they should be allowed to dry in areas free of contamination before they are sealed into evidence bags, when possible.

Another fairly common example of biological evidence found at the scene of an animal crime is the body of a deceased animal. The animal’s body can provide crucial information for the case and should be handled carefully during collection. At the scene, the paws are often covered with paper bags and the body wrapped in a clean sheet prior to being placed in a bag so that trace evidence is not lost during transit (DiMaio & DiMaio, 2001; Touroo & Fitch, 2016). The handling and collection of evidence from deceased animals, as well as necropsy protocols, will be discussed in Chapter 10.

A later section will address personnel safety during crime scene investigations, but it bears repeating that when handling biological samples, the investigator must take reasonable caution against contaminating the samples with their DNA or cross-contaminating samples. In addition, the investigator must be very careful not to expose themselves to any pathogens contained in the biological samples. The use of disposable gloves that are changed between the collections of samples is standard ,and many investigators use the double-glove technique to minimize exposure to pathogens.

The International Association of Property and Evidence, Inc. published an online manual for detailing the professional standards of managing and storing evidence. Many of generalities that apply to evidence collection and storage for human crime scenes will also be applicable to animal crime scenes (International Association for Property and Evidence Inc., 2016).

Unique to animal cases is the presence, collection and preservation of live evidence—the animals themselves. Because of the unique challenges of live evidence, the collection, documentation, and preservation (housing) of live evidence will be discussed in detail in the following sections.