Illinois V. Caballes - Dissenting Opinions

Dissenting Opinions

Justice Souter believed that the time had come to revisit the essential premise underpinning both the Court's opinion in United States v. Place and the majority's opinion in Caballes—that the sniff of a dog is infallible, and can reveal either the presence or absence of narcotics and nothing else. "The infallible dog, however, is a creature of legal fiction.... Their supposed infallibility is belied by judicial opinions describing well-trained animals sniffing and alerting with less than perfect accuracy, whether owing to errors by their handlers, the limitations of the dogs themselves, or even the pervasive contamination of currency by cocaine." Souter pointed to a study relied on by the State of Illinois in its reply brief, indicating that "dogs in artificial testing situations return false positives anywhere from 12.5% to 60% of the time, depending on the length of the search." If a dog is not infallible, then there is no logical basis for the sui generis rule underlying Place and Caballes, and every reason to investigate "the actual function that dog sniffs perform." Because the dogs are in the hands of government agents determined to discover evidence of crime, the dog sniff is the "first step in a process that may disclose intimate details without revealing contraband," and hence is a "search" within the meaning of the Fourth Amendment. In the context of a traffic stop, an additional search unrelated to the initial purpose of the stop requires reasonable suspicion. Since in this case the police did not have such suspicion, Justice Souter would have affirmed the decision of the Illinois Supreme Court.

Justice Ginsburg focused on the long-standing connection in the Court's Fourth Amendment jurisprudence between a traffic stop and the stop-and-frisk authorized in Terry v. Ohio. The scope of a Terry stop is not circumscribed merely by duration; the manner in which the stop is carried out must also be carefully controlled. Ginsburg would have applied this principle to the traffic stop in this case, and required reasonable suspicion for the police to transform the routine traffic stop into a more extensive search for drugs. The fact that a dog sniff is sui generis only matters if the sole determinant of what is "reasonable" is the length of time a traffic stop lasts. If the Court had recognized that traffic stops must be limited in what police are searching for as well as how long they take to conduct the search, the sui generis nature of dog sniffs would not have been dispositive of the case. "Under today's decision, every traffic stop could become an occasion to call in the dogs, to the distress and embarrassment of the law-abiding population.... Today's decision clears the way for suspicionless, dog-accompanied drug sweeps of parked cars along sidewalks and in parking lots.... Motorists have constitutional grounds for complaint should police with dogs, stationed at long traffic lights, circle cars waiting for the red signal to turn green."