In a 6-2 decision published Jan. 24, the Supreme Court ruled that a dog sniff conducted during a lawful traffic stop that reveals no information other than the location of an unlawful substance does not violate the Fourth Amendment.
The case arose from a traffic stop made by Illinois State Trooper Daniel Gillette on an interstate highway. Gillette stopped the respondent, Roy Caballes, for driving six miles an hour over the speed limit. When Gillette radioed the police dispatcher to report that he was making the stop, Trooper Craig Graham, an interdiction and canine officer, heard the transmission and headed to Gillette’s location.
Graham, who arrived while Gillette was conducting a background check on Caballes and issuing him a warning ticket, walked his dog around Caballes’ vehicle. The dog alerted on the rear of the vehicle, prompting the troopers to search the trunk. They found 282 pounds of marijuana and arrested Caballes.
A trial court judge denied Caballes’ motion to suppress and convicted him of a narcotics offense. Caballes received a 12-year prison term and was fined $256,136. An appellate court upheld the trial court’s ruling on the motion to suppress, but the Illinois Supreme Court overruled the appellate court, finding that the troopers’ actions were unlawful.
The U.S. Supreme Court overturned the Illinois Supreme Court ruling.
Justice John Paul Stevens, the author of the opinion, noted that the officers had not “unnecessarily prolonged the stop and that the dog alert was sufficiently reliable to provide probable cause to conduct the search.”
Stevens wrote that the court agreed to review the case on the narrow question of “whether the Fourth Amendment requires reasonable, articulable suspicion to justify using a drug-detection dog to sniff a vehicle during a legitimate traffic stop.”
In making its determination the court found:
The initial (stop) seizure of the respondent was based on probable cause and (concededly) legal;
A seizure that is justified solely by the interest in issuing a warning ticket can become unlawful if it is prolonged beyond the time reasonably required to complete that mission;
Because the dog sniff was performed on the exterior of the vehicle while the respondent was lawfully seized, any intrusion on his privacy expectations did not rise to the level of a constitutionally cognizable infringement because the narcotics-detecting dog exposed only illegal drugs and not other items that would otherwise be hidden from view.
Justice Stevens cited United States v. Place, 462 U.S. 696 (1983) – a case in which the court held that a dog sniff is not a search – in pointing out the importance of using a well-trained narcotics detection dog for sniff purposes.