Drug-sniffing dogs have high error rates in detecting narcotics and their alerts may not establish probable cause for searches. If searches involving K9 units are declared unlawful because Fourth Amendment rights are violated, any evidence seized in the search can be suppressed. Many drug charges involving K9 detection are dismissed before the case ever proceeds to trial.
How Accurate are Drug-Sniffing Dogs?
Drug-sniffing dogs are not very accurate when it comes to discerning the presence of illegal drugs. Multiple studies show alarmingly high error rates, with some results exceeding 50 percent.
According to a recent Washington Post article, the Supreme Court is reviewing a case that questions the use of drug-sniffing dogs. The suspect in the case was suspected of dealing drugs out of his Minnesota apartment. Police initiated a search of the building using drug-sniffing dogs that alerted to smells in the hallway. Drugs were discovered inside and the suspect was charged with drug trafficking. He filed a motion to suppress the evidence, claiming his Fourth Amendment rights had been violated.
Drug detection dogs are trained by their police handlers who use rewards when the animal “alerts”. To begin training, the handler plays a game of tug with the dog using an unscented white towel. Later, some type of narcotic such as marijuana is rolled up inside the towel. Eventually, the dog starts to recognize the smell and associate it with the game and his reward.
After dogs are certified as drug-detection dogs, there is no oversight for testing the dog’s accuracy for sniffing out narcotics. As long as the dogs complete certified training, they may be used as drug-sniffing dogs by their police handlers, even if their rate of accuracy is below par compared to other dogs. It’s up to police handlers to properly train and certify their dogs for duty.
Many police handlers cue their dogs to alert on command. In such cases, dogs often alert to the presence of drugs when no drugs are present. Videos of roadside searches show indicators that drug-sniffing dogs were cued by their handlers to alert. Since dogs are sensitive to body language, they may alert based on the handler’s body language signals. These issues raise serious legal concerns about narcotic searches and seizures when drug-sniffing dogs are involved.