As we know dogs have an incredible sense of smell. Some dogs, such as the bloodhound, has a sense of smell 1000 times better than a human's. This attribute is used by the police force every day, using dogs to 'sniff out' the likes of drugs and to find missing people. Dogs can follow a scent for miles, over great distances in any weather. And yet how is this useful to the forensic investigator?

It has been proven without a doubt that dogs are capable of sniffing out almost anything anywhere, so long as they are given a scent to follow. In the past they have been used in criminal investigations to track down missing people and even missing evidence. However even today evidence sought out by dogs is not always accepted. In Britain evidence from a dog is inadmissible in court, yet it is accepted in Holland, Germany, Hungary and some parts of the United States. Even though through countless experiments the uncanny power of the dog's sense of smell has proved to be an invaluable tool, some countries still do not allow dog evidence.

In criminal investigations the breeds of dog most commonly used are the Bloodhound and the German Shepherd. These breeds of dog have been proven to be the most loyal, reliable and with the best sense of smell, therefore valuable to the police force and even forensic investigators.