Let’s admit something first: as crime scene investigators, we sometimes get called to scenes that we consider a waste of time because we assume we can’t do much. This is especially true for scenes involving animals. These cases are often euphemistically referred to as “dog calls,” or in less polite circles, by another term for male bovine excrement. But if we look more critically at what crime scene investigators can bring to the table, we may realize that we have been too dismissive of a “dog call.” Most of us entered this field to help others by using science to solve crimes. We need to recognize that the skills we’ve acquired can also be applied to helping animals. Like many of our human victims, animals are unable to speak for themselves. When an animal is the victim of a crime, we can use our skills to work the scene. Doing so can be just as important as using our skills to work any other case. 

Owen McDonnell

What kind of animal crime scenes are CSIs likely to encounter? In many jurisdictions, crimes involving animal neglect, animal cruelty and dog fighting remain a problem. Keep in mind that in many instances, serial killers have a history of torturing small animals. I have investigated allegations of neglect of both large and small animals. These cases range from failure to keep adequate food and water to animals who can barely stand due to poor nutrition. Cruelty cases can involve mistreatment of animals and may range from chaining animals outside without shelter in severe weather to outright torture of animals. Dog fighting, while in the shadows, is big business and often involves cruelty, gambling and drug usage. Domestic dogs are often stolen and used to train fighting dogs. Dogs that lose during fights are frequently killed and discarded with tell-tale injuries associated with fighting. 

Working a crime scene involving animals can present challenges. For instance, proving animal cruelty will require the services of a veterinarian. But remember that animal crime scenes can be worked using the same methodologies we use every day. The ASPCA maintains a veterinary Forensic Sciences Team that utilizes the same process CSIs use in their daily work: assessment, observation, documentation, scene search, evidence collection and packaging, followed by analysis of collected evidence. In some areas, an ASPCA Animal Crime Scene Investigation team may respond to the scene to assist. Even if an investigation team is not available in your area, an ASPCA Field Investigator can be an excellent resource if you are called to investigate an animal-related crime. 

When you’re charged with investigating these types of scenes, follow the same process you use for other cases. Begin by assessing and observing the scene. Note points of entry and exit. Consider the possibility of additional scenes. Was the animal injured or killed in a different location? Was the animal transported in a vehicle? Before you begin processing the scene, establish a perimeter and take the proper steps to ensure your safety.  Before you begin processing, document the scene with photography, sketches and perhaps video. This creates a record of the animals and their surroundings prior to anything being moved. Keep in mind that violence by the offenders is a distinct possibility. Have adequate security in place to allow you to perform your duties safely.  

As in any case, the evidence you collect is crucial. As you search the scene, look for evidence that may be relevant to the victim and to the suspect(s). At the scene of a suspected dog fight, be sure to collect blood evidence, which can provide a link to the involved dogs, and ultimately to their owners. The University of California Davis Veterinary Medicine is home to the first Canine CODIS. This system was developed as a cooperative venture of the Missouri Humane Society, the ASPCA, the Louisiana SPCA and the UC Davis Veterinary Genetics Laboratory. In addition, air, fiber, fingerprints, tire and shoe prints may provide probative value in these cases, just as in every criminal investigation. Blood may also be a critical issue in cruelty or neglect cases. Check the instruments used to mistreat or torture animals; they may also yield blood, hair or tissues. Don’t overlook anything; something you discover may be the key to your case. Check with your local and state labs to see if they perform analysis; if not, the ASPCA may be able to recommend labs such as the UC Davis Veterinary Medicine Lab. Private labs may also be available to provide these services on a fee basis. 

Keep in mind the fact that DNA is present in all living things and can be as probative in animal cases as in human cases. DNA has been used to track illegal ivory trafficking and determine hotspots for poaching in Africa. Species identification through DNA has assisted wildlife and fisheries agents in their cases for years. In 1979, the United States Department of Wildlife and Fisheries hired crime lab director Ken Goddard to set up a forensic program for wildlife law enforcement. Early work focused on the creation of crime scene investigations, evidence handing and forensics to their law enforcement manual. These efforts ultimately resulted in the creation of a dedicated forensic lab later named the Clark R. Bavin National Fish and Wildlife Laboratory in Ashland, Oregon. While their lab only provides analysis of federal wildlife protection law investigations, many states offer similar analysis related to state hunting and fishing violations. 

In addition, remember that animal evidence can also assist in our other investigations. Everyone has noticed dog or cat hair on their own clothing on occasion. Locard’s Exchange Principal works overtime when domestic animals are present in homes. How can this help us with human cases? Just as when we sit on furniture in a house with pets present, criminals especially in rape and homicide cases, often come into contact with pet hair during the offense. When this happens, it is transferred to their clothing and leaves the scene with them. While shed hair often does not contain nuclear DNA, it carries mitochondrial DNA that can assist in the investigation. If a suspect is found and hair is noticed on his clothing, the hair should be collected for further examination. Just as in human DNA cases, we need to collect reference samples from the animals at the scene. I am not saying that you should collect dog and cat hair at every scene, but if this type of evidence is found later, be sure to go back and collect reference samples from the animals at the scene. 

No matter the scene, correct processing requires attention to detail, documentation and evidence collection. Animal-related scenes can be difficult. After all, it can be a bit tricky at times taking a buccal swab from an animal. It may take some creative safety techniques to keep from being bit or clawed. But the question should again be, why not?

Owen McDonnell retired as the Lieutenant/Supervisor of the Caddo Sheriff’s Office Crime Scene Investigations Division in Shreveport, LA after 31 years. He is the owner of M.O. Forensics LLC and provides consulting and training in crime scene and fingerprint development and comparison techniques, as well as heading workshops through IAI.