Police scent dogs were wrong 100% of the time in alerting their handler to the presence of drugs during
sweeps of schools in Janesville, Wisconsin. During sweeps at six middle and high schools the scent dogs gave 80 alerts for the presence of drugs in a student’s locker — and no drugs were found in any of the lockers. The dogs also falsely detected drugs in 13 cars during a sweep of the parking lot at two high schools. The sweep of a high school in nearby Edgerton by police scent dogs resulted in 9 alerts for drugs when none were present. So in those sweeps the dogs falsely alerted for drugs a total of 102 times — without correctly detecting drugs a single time.
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Belgian shepherd (dogchannel)
The inability of the scent dogs to reliably detect drugs during the school sweeps is consistent with the finding of a recent double blind experiment involving 18 certified police scent dog/handler teams that found they were wrong 85% of the time in detecting drugs and/or explosives. An article about that experiment, “Handler beliefs affect scent detection dog outcomes,” was reported in the January 2011 issue of the journal Animal Cognition.
The scent dogs used to sweep the schools were certified to detect marijuana, cocaine, heroin and methamphetamines. The scent dogs inability to reliably detect drugs suggests the certification process is flawed since it does not involve a double-blind test to determine a dog’s competence. A double-blind test is one in which the dog’s handler doesn’t know if there are any drugs in an area the dog is assigned to search or where those drugs might be located. The experiment of the 18 police scent dog/handler teams also supports that a handler sends conscious or unconscious cues to his dog where drugs or explosives are believed to be located. Consequently the only way to determine a scent dog’s competence is to administer a double-blind test that prevents the handler from tipping off the dog where to search.
Although it is now known that a scent dog’s alert for drugs and explosives is overwhelmingly likely to be false, the widely believed myth that dogs can accurately detect the presence of contraband is relied on by judges to almost automatically issue a search warrant when presented with scent dog evidence that is actually in the realm of “junk science.”
If you go to the Janesville Gazette’s website at http://gazettextra.com and enter “drugs dogs schools” into the search box a series of articles will be listed about the scent dog searches in area schools.
By Hans Sherrer
Justice Denied
