How reliable are scent dogs in identifying suspects in a police lineup?
That’s a question that’s hard to answer since — in the US at least — there are no national standards and no system in place to keep track of a dog’s or a handler’s accuracy rate.
There’s also the question of how accuracy is determined.
In a typical dog-scent lineup, police rub a piece of gauze on a suspect’s skin or clothing. The gauze is then placed in a tin can and placed on the floor in a line with other cans containing gauze from other suspects or controls. The dog’s handler exposes the dog to a scent from the crime scene or from the victim, and the dog and handler then walk along the line of cans. When the dog detects the matching scent, it signals the handler by either stopping beside the can or barking at it.
It sounds like a simple, fool-proof system. Unfortunately, since no one speaks “dog,” it’s impossible to know what’s really going through the canine mind. How certain is the dog that it’s found a matching scent? Could something else be triggering the dog’s reaction? Could the handler — consciously or otherwise — direct the dog to a specific can?
And what if the suspect chosen by the dog is convicted, but then that conviction is later overturned? Is the dog’s record or the handler’s record updated to reflect that wrongful conviction? Is there even a record kept?
(See my post from August 5th about Bill Dillon, wrongfully convicted and imprisoned for 26 years after being tracked down by a scent dog.)
Michael Buchanek, knows all too well the danger of relying on dog-scent lineups.
Buchanek was a commander of operations with the Sheriff’s Office in Victoria County, Texas for more than 25 years when, in March 2006, he was accused of murdering his friend and neighbor, Sally Blackwell. His former friends and coworkers on the force were fully convinced of his guilt and turned to scent dogs to pinpoint him in a scent lineup.
Buchanek was not convicted. Five months after he was sniffed out by the dogs, another suspect was identified with DNA evidence and confessed to the crime. But the career officer says the incident has left him with a bad taste for law enforcement. “It’s pretty much ruined my life altogether.”