Wednesday, November 4, 2009

Dog "Scent Line Ups" Unreliable and Misused

The New York Times today reported on the phenomenon of dog "scent line ups", in which a dog is exposed to a scent from a crime scene and then walked past vials containing swabbed samples from suspects and non-suspects. The dog indicates to the handler that it has reached a match, by stiffening its back or barking. Using dogs to follow scents has long been a practice of law enforcement officials, and is still employed by the FBI. But even the FBI agrees that dog scent line ups should not be used as the primary piece of evidence against a suspect. Dogs are liable to suggestion by their handlers, smells are often easily mixed and difficult to distinguish, and handlers may misinterpret their dog's signals. Many states do not accept scent line ups as evidence, but several do, including Texas, Florida, New York and Alaska.

New York Times: