Dog bites to kidnapping: how King's Forensics uses canine DNA to solve crime

The spirit of Rosalind Franklin lives on at King’s. Her discovery of the helical structure of the molecule, leading to its iteration in the double-helix described by Watson and Crick in 1953 has had a profound influence on the biological sciences. Just over thirty years later Alec Jeffreys understood how visible patterns in the molecule could be used to determine a familial relationship and employed his methodology to solve the murders of two young girls in Leicester, transforming forensic science for the future. Research in forensic genetics continues world-wide and here in King’s Forensics we also continue that journey to provide more intelligence about a crime from material that not infrequently consists of only a handful of cells that are also often damaged by the environment in which they are found.

It is not just human DNA that can provide important evidence in a criminal case and, in collaboration with the Royal Veterinary College, we have been researching the ability to use similar techniques applied to canine DNA that we can use to assist forensic cases.

Dogs are a common presence in human society and the ability to reveal a canine source of material at a crime scene and also provide genetic information for a robust identification can transform an investigation. While dogs may be responsible for some crimes, maiming or even leading to the death of a human, for example, they may also be the subject of a criminal attack on the dog. Dogs are also often responsible for attacks on livestock that are a significant million pound annual cost to farmers. Without something like a human DNA database, the identification of the animal from canine material is obviously problematic if there is no dog to compare to.

Breed identification, like human origin testing, is offered by commercial companies. It requires a significant amount of uncompromised material from the dog, which is often not available at a scene where a dog has been involved. Our research seeks to be able to infer the likely breed or type for intelligence purposes from these often tiny and compromised samples, looking for patterns in the data to provide guidance as to what the dog might look like to assist in the investigation.

It's not only direct involvement of a dog in a crime that can provide useful information to an investigation. Dogs are frequently bystanders to a crime and may leave their hairs at a crime scene, or on a victim. In current forensic casework such evidence may simply be determined as non-human and not considered further. However now we can sequence the mitochondrial DNA in the hair which could provide an important link to human perpetrators in cases such as kidnapping or illegal detention of humans.