Alternate Light Source Examination

A blacklight (UV or Wood’s lamp) or other ALS should be used to examine the entire body for the presence of any proteinaceous substance (i.e., semen, saliva, vomit, or blood) which is more likely to be visible when illuminated. Any evidence found with the blacklight or ALS should be swabbed or collected (snipping clumps of fur) and documented.

The preferred ALS to detect human semen is a wavelength of 420-450 nm, viewed through orange lenses. Most veterinary hospitals have a Wood’s lamp on hand, and this light emits a wavelength of 300-400 nm. The Bluemaxx BM500 (Sirchie; Medford, NJ) is recommended as a more specific light source to detect human semen (Stern and Smith-Blackmore, 2016).

The entire animal should be examined with an ALS to detect proteinaceous deposits (semen, saliva, or blood), scanning the entire body in a systematic pattern. The location on the body where the evidence was collected should be recorded in notes and sketches. An ALS may also identify an injury that is not yet visible.

Infrared thermal imaging may assist in the detection of areas of trauma and inflammation in the living patient. Thermal imaging can be used to map blood flow and areas of increased blood flow. There are a variety of thermal imaging cameras available on the market, including a cell phone adaptor.

Trace Evidence

When ASA is suspected, measures should be taken to collect and preserve trace evidence such as body fluids, lubricants, fibers, and foreign hairs. The principle in forensic science related to trace evidence is known as the Locard exchange principle.

Edmund Locard was a French criminalist known as the "Sherlock Holmes of France.” He is best known for formulating the basic principle of forensic science which became the cornerstone of forensic science: “Human contact with any person, place or thing, will result in an exchange of physical materials or evidence” (Bader and Gabriel, 2010). This pertains to all crime scenes, living and inanimate.

All first responders and examiners should be aware of the Locard exchange principle and allow for this when handling, transporting, and performing a medical-forensic exam on animal victims. It is imperative that first responders note contact and activities that have occurred from the time of the suspected assault until the animal is in the forensic examiner’s possession.

Contact with the animal should be minimized, and everyone who has contact with the animal needs to understand that the animal is the crime scene and treat them as such. This means not grooming an animal until after the forensic exam is conducted, separating animals into individual primary enclosures, and placing an e-collar on the animal until the exam is conducted to prevent self-grooming. Whenever possible, animals should be transported in clean airline transportation crates lined with a clean white sheet or clean cage liners.