The NACDL and the ACLU also describe a 1984 operation in which Florida state police stopped about 1,330 vehicles at roadblocks and walked dogs around them. If one dog alerted, another was brought in, and vehicles were searched only if both dogs indicated the presence of illegal drugs. That happened 28 times, but those searches yielded just one drug arrest. "Despite the requirement that two dogs alert before a search," the NACDL/ACLU brief notes, "police found illegal narcotics sufficient to justify an arrest in only 4% of cars searched," meaning "the likelihood of a false alert was approximately 96%." With impressive chutzpah, Florida's lawyers claim "this example at most shows a 'false' alert rate under 2%." You see what they did there ? Twenty -seven false alerts divided by 1,330 cars equals 2 percent. But the relevant question is not the percentage of vehicle stops that resulted in a false alert; it is the percentage of alerts (in this case, double alerts) that turned out to be false. For purposes of probable cause, we want to know the likelihood that a search triggered by a dog's alert will find drugs. In this case it was 4 percent—not, as Florida's tricky calculation implies, 98 percent.
What is going on when a dog alerts and no drugs are found ? Police and prosecutors want us to believe these are not really false alerts at all: Either the drugs were so cleverly hidden that the cops could not find them, or the dog detected otherwise imperceptible traces left by drugs that were recently in the vehicle or by contact with drug users' hands (which is what the prosecution claimed in Harris). But these explanations are completely unfalsifiable and amount to nothing but self -serving speculation. Furthermore, the "residual odor" excuse weakens rather than strengthens the case for probable cause, since the traces could have been left by someone other than the driver: a passenger, a previous owner, even (as the defendant's lawyers in Harris suggest) a cash -strapped addict who tried to open the vehicle's door while looking for stuff to steal. In addition to residual odors, dogs can be confused by the smells of food, other dogs, and legal chemicals they have been trained to associate with drugs. But perhaps the biggest source of error is the cues that dogs pick up from their handlers, whose expectations can influence the animals' behavior.
LOL! There are two organizations you must be proud to represent. If sniffer dogs are so inept, why are they used in search and rescue, explosives and bomb detection in both civil and military operations ?