Drug-Sniffing Dogs: Accurate Crime-Fighters or Tool of Deceptive Police?

Police K-9’s: we’re led to believe they have been trained in the best dog academies to use their superior sniffers to identify illicit drugs. They are essentially used to find drugs when cops themselves can’t identify their presence. But not all research backs up their use, with some even indicating the dogs are mere extensions of what their handlers expect them to find. Still, like shields, tanks and flash-grenades, they are common tools in the Drug War that law enforcement across the country insists on waging.

The most recent study on drug-sniffing dogs had (mostly) good things to say about the canines—that they were right more often than they were wrong. But the study published in Forensic Science International seems to have been written with validating police practices as an end goal.

The study abstract reads, “Our experiments do not confirm the recent reports, based on drug users’ opinions, of low drug detection efficiency.”

The researchers, mostly from The Institute of Genetics and Animal Breeding of Police Academy of Sciences, must not be hip to the fact that “drug users” are far from the only ones critical of the use and accuracy of police dogs. Further, they seem to be overinflating their findings.

drug sniffing dogs and false positivesThe dogs were on their best performance when they searched an individual room where they had previously been allowed to conduct a sweep. In those rooms, they correctly located drugs 83 percent of the time, but still provided false-alerts in 10 percent of the searches. When it came to searching vehicles, the situation we most often see K-9 police dogs being used, they were far less accurate.

Dogs used in mock traffic stops only correctly alerted to the presence of drugs 64 percent of the time. That’s just a little over half. In 15 percent of the runs, the dogs failed to recognize the presence of contraband, and in 22 percent they indicated the presence of drugs when no drugs were present at all. Inside cars, they provided false alerts some 36 percent of the time.

Despite the picture the researchers paint on the front page of their study, these are far from reliable results, particularly when we are talking about searches that are often only loosely justified.

Again, drug users aren’t the only ones concerned about drug-dog accuracy. The researchers involved with that particular study would do good to read one from the University of California- Davis, published in 2011, where scientists found the performance of police drug dogs is directly related to their handlers’ beliefs on whether drugs will be found or not.

In the Davis study, published in Animal Cognition, the researchers tested 18 teams of drug or bomb-detecting dogs and their handlers, putting them in situations where the handler was sometimes led to believe that the dog would alert. In those situations, the dogs were more likely to “hit” on contraband, whether or not contraband was actually present.

As the author’s put it, “Handlers’ beliefs that scent was present potentiated handler identification of detection dog alerts. Human more than dog influences affected alert locations. This confirms that handler beliefs affect outcomes of scent detection dog deployments.”

No “drug users” were used in this study. As a matter of fact, the researchers didn’t even consider their drug users’ opinions.

No matter who has them, concerns over the validity of drug-dog use are valid. Just a few years ago, a group of Nevada Highway Patrol troopers spoke up, filing a racketeering complaint against the NHP and Las Vegas Metro Police Department, alleging the head of the Patrol intentionally undermined the intent of the K-9 program being used to target drug runners on Nevada highways.

According to the complaint, “the drug-sniffing dogs used by troopers in the program were intentionally being trained to operate as so-called trick ponies, or dogs that provide officers false alerts for the presence of drugs.”

A false-alert from a dog would allow the police to illegally search and seize evidence, including money and property.

The Supreme Court ruled in Illinois v. Caballes in 2005 that a dog’s alert during a traffic stop justified the police search of a vehicle. In other words, the dog’s alert provided probable cause that drugs were present. But, police can’t have a drug dog “case” the outside of your vehicle without first having reasonable belief that contraband is inside.

Example: You are pulled over for driving erratically. The officer can use your driving behavior paired with what he says is the smell of marijuana as justification to have his dog smell around the outside of your vehicle. If that dog “hits” on the smell of contraband, he can use that as justification to search inside your vehicle and potentially arrest you if any drugs are found.

It’s not that “drug users” and highly esteemed scientific researchers, or simply informed citizens are concerned the dogs aren’t good enough at their job, or that they are bad at sniffing out drugs (though the latest study did indicate they aren’t reliable as they maybe should be). The mistrust isn’t on the dogs, but on their handlers and trainers.

It’s true, not all K-9 officers are bad guys just as not all politicians are liars, but it seems the science and behavioral factors behind canine drug identification make it a dangerous tool when in the wrong hands.


About David Matson