Not long after we all fell in love with CSI and the science behind forensic evidence, much of that science was called into question. Beyond the accidental errors and purposeful evidence tampering at crime labs and by lab technicians, it turns out that the underlying basis for many types of forensic evidence was flawed.

Now, another long-trusted crime fighting aide is coming under scrutiny. As Radley Balko writes for The Washington Post, it turns out drug sniffing dogs aren’t especially good at sniffing out drugs. And this news should have an impact on a big case pending in the Supreme Court.

Passing the Smell Test?

Primarily based on misconceptions about their accuracy, dog sniffs have long been an exception to the search warrant requirement. In fact, interactions with drug sniffing dogs in public aren’t thought to be intrusive enough to be considered “searches” under Fourth Amendment law. As the Supreme Court said in 2005: “A dog sniff conducted during a concededly lawful traffic stop that reveals no information other than the location of a substance that no individual has any right to possess does not violate the Fourth Amendment.”

But the dog sniffs may not be as accurate as we thought, and searches based on false hits may be incredibly intrusive. As Balko notes:

While dogs are indeed capable of sniffing out illicit drugs, we’ve bred into them another overriding trait: the desire to please. Even drug dogs with conscientious handlers will read their handlers’ unintentional body language and alert accordingly. A 2010 study found that packages designed to trick handlers into thinking there were drugs inside them were much more likely to trigger false alerts than packages designed to trick the dogs … Many drug dogs, then, are not alerting to the presence of drugs, but to their handlers’ suspicions about the presence of drugs. And searches based on little more than law enforcement’s suspicions are exactly what the Fourth Amendment is supposed to prevent.

Who Polices the Police Dogs?

As it stands now, police may conduct drug dog sniffs of vehicles as long as the initial stop was legal and it doesn’t take too long to get the canine officer to the scene. However, police are required to get a warrant before a dog can search your home. And the Supreme Court will soon decide whether drug dogs sniffing outside an apartment door similarly requires a warrant. (As Balko points out, if not, “police could take their dogs up and down apartment complexes the way they sometimes do with school lockers.”)

Some studies have shown that drug-dog alerts aren’t always correct, and in fact can be wrong up to 50 percent of the time. Those false positives can lead to further searches, and in some cases, property being seized and never returned. Still, most courts have been unreceptive to increased scrutiny of dog search accuracy, and have limited arguments to time and place.

If you think you’ve been the victim of an illegal dog search, contact an experienced criminal defense attorney as soon as possible.

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