In 2010, a team of researchers at the University of California, Davis set out to test the reliability of drug- and bomb-sniffing dogs.
The team assembled 18 police dogs and their handlers and gave them a routine task: go through a room and sniff out the drugs and explosives.
But there was a twist. The room was clean. No drugs, no explosives.
In order to pass the test, the handlers and their dogs had to go through the room and detect nothing.
But of 144 runs, that happened only 21 times, for a failure rate of 85 percent.
Although drug-sniffing dogs are supposed to find drugs on their own, the researchers concluded that they were influenced by their handlers, and that's what led to such a high failure rate.
The reliability of drug dogs and their handlers is at the heart of a lawsuit filed in state district court by two Nevada Highway Patrol K-9 troopers and a consultant, who claim that the Metropolitan Police Department's police dogs, and eventually NHP's own dogs, were "trick ponies" that responded to their handlers' cues, and therefore routinely violated citizens' rights to lawful search under the Fourth Amendment.