The U.S. Supreme Court recently heard Florida v. Harris, a Florida case concerning the use of police dogs in traffic-stop searches. The case addresses indicia of reliability and hence legality of narcotics sniffing dogs under 4th Amendment search and seizure.
Essentially, the case is about whether a drug-detection dog must have proven reliability in the field and what is sufficient to show such reliability. The U.S. Supreme Court held that searches demand a "flexible, common-sense standard," and that it is not necessary to produce exhaustive records about drug-detection dogs' training and reliability in order to have probable cause for a vehicle search.
The facts of the case are relatively straightforward. During a routine traffic stop, a police officer pulled the defendant over. The police officer noticed that the defendant appeared nervous, and he had an open beer can in his car. The police officer asked the defendant if he could search the car, and the defendant refused. The police officer then led his trained narcotics dog around the defendant's. The dog signaled the presence of drugs. Because of the dog's alert, the police officer determined that he had probable cause to which is required for a search.
The police officer searched the defendant's car. During that search, he found pseudoephedrine and other illegal ingredients used to manufacture methamphetamine. The police officer arrested the defendant for illegal possession of the ingredients, although none of them were substances that the dog was actually trained to detect.
When the defendant was out on bail, the police officer stopped him again for a broken brake light and the dog alerted again, but the police officer didn't find any illegal substances--"nothing of interest was found."
The defendant moved to suppress the evidence found in his car (the ingredients for manufacturing methamphetamine) by arguing that the dog's alert didn't give the police officer reasonable cause for a search. The defendant emphasized that the dog wasn't trained to detect the type of drug ingredients found, and that the dog had a false positive during the second search.
The trial court ruled that the search was legal, and the defendant appealed. The case then went to the Florida Supreme Court in 2012. That court there decided in favor of the defendant, finding that it's necessary to have extensive records of a drug-detection dog's training and field reliability in order for a search to be legal. It said that mere proof of a dog's training and certification "is simply not enough." The Florida Supreme Court emphasized a need for "evidence of the dog's performance history." The state appealed to the U.S. Supreme Court, which overruled the Florida Supreme Court's decision.
The U.S. Supreme Court emphasized that, in cases concerning probable cause for a search, it looks to a "totality of the circumstances." This means simply that it looks to all the factors involved in order to determine whether a reasonable person would believe that there was evidence of illegal drugs or other contraband materials, making the search legal.
The U.S. Supreme Court described this standard as a "practical" and "common-sensical" one, and emphasized that it rejects "rigid rules" and "bright-line tests" like the one proposed by the Florida Supreme Court. Instead, in situations concerning probable cause for a search, police officers can be "flexible," taking an "all-things-considered approach." For the U.S. Supreme Court, a dog's training and certification is sufficient to say that the dog is capable of sniffing out illegal substances and properly alerting a police officer. Training records alone are enough to establish reliability.
This ruling seems to ignore the fact that dogs, like humans, have different abilities. Training alone does not make a dog any more competent than a human. In fact, it seems that the reliability of the dog can only be measured by its history of service. There may be dogs, like humans, that are predisposed to false alerts creating overboard searches which is the very thing that is prohibited by the 4th Amendment.