United States v. Sharpe, 470 U.S. 675 (1985)
Syllabus
A Drug Enforcement Administration (DEA) agent, while patrolling a highway in an area under surveillance for suspected drug trafficking, noticed an apparently overloaded pickup truck with an attached camper traveling in tandem with a Pontiac. Respondent Savage was driving the truck, and respondent Sharpe was driving the Pontiac. After following the two vehicles for about 20 miles, the agent decided to make an “investigative stop,” and radioed the South Carolina State Highway Patrol for assistance. An officer responded, and he and the DEA agent continued to follow the two vehicles. When they attempted to stop the vehicles, the Pontiac pulled over to the side of the road, but the truck continued on, pursued by the state officer. After identifying himself and obtaining identification from Sharpe, the DEA agent attempted to radio the State Highway Patrol officer. The DEA agent was unable to contact the state officer to see if he had stopped the truck, so he radioed the local police for help. In the meantime, the state officer had stopped the truck, questioned Savage, and told him that he would be held until the DEA agent arrived. The agent, who had left the local police with the Pontiac, arrived at the scene approximately 15 minutes after the truck had been stopped. After confirming his suspicion that the truck was overloaded and upon smelling marihuana, the agent opened the rear of the camper without Savage’s permission and observed a number of burlap-wrapped bales resembling bales of marihuana that the agent had seen in previous investigations. The agent then placed Savage under arrest and, returning to the Pontiac, also arrested Sharpe. Chemical tests later showed that the bales contained marihuana. Respondents were charged with federal drug offenses, and, after the District Court denied their motion to suppress the contraband, were convicted. The Court of Appeals reversed, holding that, because the investigative stops failed to meet the Fourth Amendment’s requirement of brevity governing detentions on less than probable cause, the marihuana should have been suppressed as the fruit of unlawful seizures.
Held: The detention of Savage clearly met the Fourth Amendment’s standard of reasonableness. Pp.  470 U. S. 682-688.
(a) In evaluating the reasonableness of an investigative stop, this Court examines
“whether the officer’s action was justified at its inception, and whether it was reasonably related in scope to the circumstances
Page 470 U. S. 676
which justified the interference in the first place.”
Terry v. Ohio, 392 U. S. 1,  392 U. S. 20. As to the first part of the inquiry, the Court of Appeals assumed that the officers had an articulable and reasonable suspicion that respondents were engaged in marihuana trafficking, and the record abundantly supports that assumption, given the circumstances when the officers attempted to stop the Pontiac and the truck. As to the second part of the inquiry, while the brevity of an investigative detention is an important factor in determining whether the detention is unreasonable, courts must also consider the purposes to be served by the stop, as well as the time reasonably needed to effectuate those purposes. The Court of Appeals’ decision would effectively establish a per se rule that a 20-minute detention is too long to be justified under the Terry doctrine. Such a result is clearly and fundamentally at odds with this Court’s approach in this area. Pp. 682-686.
(b) In assessing whether a detention is too long in duration to be justified as an investigative stop, it is appropriate to examine whether the police diligently pursued a means of investigation that was likely to confirm or dispel their suspicions quickly, during which time it was necessary to detain the defendant. Here, the DEA agent diligently pursued his investigation, and clearly no delay unnecessary to the investigation was involved. Pp.  470 U. S. 686-688.
712 F.2d 65, reversed and remanded.
BURGER, C.J., delivered the opinion of the Court, in which WHITE, BLACKMUN, POWELL, REHNQUIST, and O’CONNOR, JJ., joined. BLACKMUN, J., filed a concurring opinion, post, p.  470 U. S. 688. MARSHALL, J., filed an opinion concurring in the judgment, post, p.  470 U. S. 688. BRENNAN, J., post, p.  470 U. S. 702, and STEVENS, J., post, p.  470 U. S. 721, filed dissenting opinions.