This week the Supreme Court agreed to hear a case that casts doubt on the routine use of drug-sniffing dogs to generate probable cause for vehicle searches. Despite the potential for false positives due to poorly trained dogs, incompetent handlers, residual odors, subconscious cues, and misinterpretation (or misrepresentation) of a dog's behavior, courts generally accept a canine "alert" as adequate justification for a search. But last year the Florida Supreme Court ruled that the Fourth Amendment requires courts to consider the reliability of such evidence and that it's not enough to ask whether a dog is officially certified to sniff out drugs:
The issue of when a dog's alert provides probable cause for a search hinges on the dog's reliability as a detector of illegal substances within the vehicle. We hold that the State may establish probable cause by demonstrating that the officer had a reasonable basis for believing the dog to be reliable based on the totality of the circumstances. Because a dog cannot be cross-examined like a police officer on the scene whose observations often provide the basis for probable cause to search a vehicle, the State must introduce evidence concerning the dog's reliability….
We hold that evidence that the dog has been trained and certified to detect narcotics, standing alone, is not sufficient to establish the dog's reliability for purposes of determining probable cause—especially since training and certification in this state are not standardized and thus each training and certification program may differ with no meaningful way to assess them….
To meet its burden of establishing that the officer had a reasonable basis for believing the dog to be reliable in order to establish probable cause, the State must present the training and certification records, an explanation of the meaning of the particular training and certification of that dog, field performance records, and evidence concerning the experience and training of the officer handling the dog, as well as any other objective evidence known to the officer about the dog's reliability in being able to detect the presence of illegal substances within the vehicle….
Because there is no uniform standard for training and certification of drug-detection dogs, the State must explain the training and certification so that the trial court can evaluate how well the dog is trained and whether the dog falsely alerts in training (and, if so, the percentage of false alerts). "Further, the State should keep and present records of the dog's performance in the field, including the dog's successes (alerts where contraband that the dog was trained to detect was found) and failures ("unverified" alerts where no contraband that the dog was trained to detect was found). The State then has the opportunity to present evidence explaining the significance of any unverified alerts, as well as the dog's ability to detect or distinguish residual odors. Finally, the State must present evidence of the experience and training of the officer handling the dog. Under a totality of the circumstances analysis, the court can then consider all of the presented evidence and evaluate the dog's reliability.
Finding that prosecutors had failed to meet this burden in justifying a dog-triggered truck search that found 200 pseudoephedrine tablets (along with muriatic acid and 8,000 matches), the court threw out a meth manufacturing charge against the vehicle's driver.
Although the Supreme Court has issued several decisions dealing with police dogs over the years, it has not squarely addressed the question of their reliability. Dissenting in Illinois v. Caballes, a 2005 decision that allowed warrantless sniffs of cars during routine traffic stops, Justice David Souter noted that "the infallible dog…is a creature of legal fiction." Souter cited examples from court cases of dogs with error rates of up to 38 percent, adding that "dogs in artificial testing situations return false positives anywhere from 12.5 to 60% of the time." Souter is no longer on the Court, but evidently at least some of the current justices see a need to re-examine the assumption that a canine alert "discloses only the presence or absence of narcotics," as the Court claimed in United States v. Place, a 1983 decision that allowed warrantless sniffs of luggage at airports on the theory that such examinations are not really searches. Maybe so, but they definitely lead to searches, and a careful consideration of whether and when they should is long overdue.
Another Florida case that the Supreme Court plans to hear, Florida v. Jardines, poses the question of whether a drug-sniffing dog at your doorstep has finally crossed the threshold of the Fourth Amendment. I discussed that case in January. More on drug-sniffing dogs here. Julian Sanchez considered the implications of Caballes in his 2007 Reason article "The Pinpoint Search."