Canine DNA: DNA Database of UK Dogs Could Transform Forensic Investigations

Forensic science is growing beyond DNA with the creation of a new canine DNA database in the United Kingdom. Experts from King’s College London and the Royal Veterinary College have created a database that includes 80 dog breeds, creating new opportunities for using dog DNA as proof in criminal cases.

Dogs can leave signs such as hair, saliva and cells at crime scenes or on people involved in an event. Before, this kind of evidence was often hard to understand because there were no canine genetic databases. The latest study uses tandem repeats (STRs)—small parts of DNA that repeat and are often used in forensic identification—to create genetic pictures of dogs. For the ten common breeds examined, including Labradors, Cocker Spaniels and Miniature Schnauzers, scientists gathered samples from at least 50 dogs of each breed.

The database can help investigators in two ways. DNA that is collected from a crime scene can be compared with DNA from a dog to decide whether that dog can be included or excluded as a possible source. If the suspected dog is unknown, the DNA profile may also give clues about its breed, helping investigators narrow their search. Researchers are also studying DNA, which can be useful when only very small amounts of biological material are available.

The method has already helped in some cases. In one situation, DNA from two dogs was discovered on clothes linked to an investigation about injuries. In another case, dog DNA found after a sheep attack ruled out the dogs that were first thought to be responsible and suggested a different type of dog was likely involved.

The progress shows how animal DNA can be useful as evidence in today’s crime investigations. Experts say that money and having enough tools for these kinds of cases are still big problems before this kind of dog DNA testing can be used more often.