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Syllabus

NOTE: Where it is feasible, a syllabus (headnote) will be released, as is being done in connection with this case, at the time the opinion is issued.
The syllabus constitutes no part of the opinion of the Court but has been prepared by the Reporter of Decisions for the convenience of the reader.
See United States v. Detroit Timber & Lumber Co., 200 U.S. 321, 337.

SUPREME COURT OF THE UNITED STATES

ILLINOIS v. CABALLES

CERTIORARI TO THE SUPREME COURT OF ILLINOIS

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After an Illinois state trooper stopped respondent for speeding and radioed in, a second trooper, overhearing the transmission, drove to the scene with his narcotics-detection dog and walked the dog around respondent’s car while the first trooper wrote respondent a warning ticket. When the dog alerted at respondent’s trunk, the officers searched the trunk, found marijuana, and arrested respondent. At respondent’s drug trial, the court denied his motion to suppress the seized evidence, holding, inter alia, that the dog’s alerting provided sufficient probable cause to conduct the search. Respondent was convicted, but the Illinois Supreme Court reversed, finding that because there were no specific and articulable facts to suggest drug activity, use of the dog unjustifiably enlarged a routine traffic stop into a drug investigation.

Held: A dog sniff conducted during a concededly lawful traffic stop that reveals no information other than the location of a substance that no individual has any right to possess does not violate the Fourth Amendment. Pp. 2—4.

207 Ill. 2d 504, 802 N. E. 2d 202, vacated and remanded.

Stevens, J., delivered the opinion of the Court, in which O’Connor, Scalia, Kennedy, Thomas, and Breyer, JJ., joined. Souter, J., filed a dissenting opinion. Ginsburg, J., filed a dissenting opinion, in which Souter, J., joined. Rehnquist, C. J., took no part in the decision of the case.