Dogs have long played a vital role in law enforcement, helping police track criminals, detect drugs, and assist in search and rescue operations. Now, researchers are exploring a new tool to help solve crimes: a database of canine DNA. While evidence such as hair, saliva, or other biological material from dogs can be found at crime scenes or on people connected to incidents, these traces are often not fully examined. Scientists believe they could provide valuable clues, such as identifying the dog involved or indicating that the dog's owner was present at the scene. Professor Denise Syndercombe Court, a forensics expert at King’s College London, explains that canine DNA can be particularly useful in cases where there is little other evidence. "If you can identify canine material associated with a crime, such as a kidnapping, that can be very powerful in helping solve a human case," she said. To harness this potential, researchers from King’s College London and the Royal Veterinary College are working together to build a database of canine DNA. However, the process is challenging. Unlike human DNA, which is more commonly available, canine DNA found at crime scenes is often limited to just a few cells. Scientists are using techniques similar to those used in human forensics, focusing on small DNA segments called short tandem repeats (STRs). These segments are repeated in the DNA, and the number of repeats provides a unique profile, much like a fingerprint. In dogs, certain STR profiles are more common in specific breeds. By analyzing these patterns, the team has created the first UK-wide database covering 80 different breeds. For the 10 most common breeds, such as labradors and cocker spaniels, they collected samples from at least 50 dogs of each breed. This database allows experts to compare DNA found at crime scenes with known profiles, either confirming or ruling out a specific dog, or identifying the breed of the dog involved. This could be especially useful when the identity of the dog is unknown or when it is not possible to collect a sample from a suspect. The team is also exploring another method of DNA analysis, focusing on mitochondrial DNA, which is found in the energy-producing parts of cells. This approach can be useful when there is very little biological material available, though it has limitations since mitochondrial DNA is only inherited from the mother. The use of canine DNA has already provided real-world insights. In one case, it helped determine that a man’s injuries were caused by his own dogs, not by another person. In another instance, DNA analysis revealed that the dogs suspected of attacking sheep were not the ones responsible, allowing investigators to narrow down the search. Experts agree that the research is promising, but challenges remain. Dr. Nicholas Dawnay, a forensic scientist at Liverpool John Moores University, emphasized the importance of studying canine DNA for crime investigations. However, he also noted that funding for forensic work involving dogs is a major issue. "Without adequate funding, the benefits of this research may not be fully realized," he said.