Thu. Jul 11th, 2024

Delaware v. Prouse – Police Cannot Just Stop Innocent People


A police officer stopped Prouse’s (defendant) car to check Prouse’s driver license and car registration. No policy or systematic roadblock required the officer to make the stop. Approaching the car, the officer smelled marijuana, saw marijuana in plain view, and seized it. Delaware (plaintiff) prosecuted Prouse for possessing illegal drugs. The trial court granted Prouse’s motion to suppress the seized marijuana. The state appealed to the Delaware Supreme Court, which affirmed the trial court’s ruling on Fourth Amendment grounds. The United States Supreme Court granted Delaware’s petition for certiorari.  A Delaware patrolman stopped William Prouse’s car to make a routine check of his driver’s license and vehicle registration. The officer had not observed any traffic violation or suspicious conduct on the part of Prouse. After stopping the car, the officer uncovered marijuana. The marijuana was later used to indict Prouse.


Did the officer’s search of Prouse’s automobile constitute an unreasonable search and seizure under the Fourth Amendment?

Rule of Law


Holding and Reasoning (White, J.)

Concurrence (Blackmun, J.)

Dissent (Rehnquist, J.)

Delaware v. Prouse, 440 U.S. 648 (1979)

Delaware v. Prouse, 440 U.S. 648, was a United States Supreme Court case in which the Court held that police may not stop motorists without any reasonable suspicion to suspect crime or illegal activity to check their driver’s license and auto registration.

U.S. Supreme Court

Delaware v. Prouse, 440 U.S. 648 (1979)

Delaware v. Prouse

No. 77-1571

Argued January 17, 1979

Decided March 27, 1979

440 U.S. 648



A patrolman in a police cruiser stopped an automobile occupied by respondent and seized marihuana in plain view on the car floor. Respondent was subsequently indicted for illegal possession of a controlled substance. At a hearing on respondent’s motion to suppress the marihuana, the patrolman testified that, prior to stopping the vehicle, he had observed neither traffic or equipment violations nor any suspicious activity, and that he made the stop only in order to check the driver’s license and the car’s registration. The patrolman was not acting pursuant to any standards, guidelines, or procedures pertaining to document spot checks, promulgated by either his department or the State Attorney General. The trial court granted the motion to suppress, finding the stop and detention to have been wholly capricious, and therefore violative of the Fourth Amendment. The Delaware Supreme Court affirmed.


1. This Court has jurisdiction in this case even though the Delaware Supreme Court held that the stop at issue not only violated the Federal Constitution but also was impermissible under the Delaware Constitution. That court’s opinion shows that, even if the State Constitution would have provided an adequate basis for the judgment below, the court did not intend to rest its decision independently on the State Constitution, its holding instead depending upon its view of the reach of the Fourth and Fourteenth Amendments. Pp. 440 U. S. 651-653.

2. Except where there is at least articulable and reasonable suspicion that a motorist is unlicensed or that an automobile is not registered, or that either the vehicle or an occupant is otherwise subject to seizure for violation of law, stopping an automobile and detaining the driver in order to check his driver’s license and the registration of the automobile are unreasonable under the Fourth Amendment. Pp. 440 U. S. 653-663.

(a) Stopping an automobile and detaining its occupants constitute a “seizure” within the meaning of the Fourth and Fourteenth Amendments, even though the purpose of the stop is limited and the resulting detention quite brief. The permissibility of a particular law enforcement practice is judged by balancing its intrusion on the individual’s Fourth Amendment interests against its promotion of legitimate governmental interests. Pp. 440 U. S. 653-655.

Page 440 U. S. 649


(b) The State’s interest in discretionary spot checks as a means of ensuring the safety of its roadways does not outweigh the resulting intrusion on the privacy and security of the persons detained. Given the physical and psychological intrusion visited upon the occupants of a vehicle by a random stop to check documents, cf. United States v. Brignoni-Ponce, 422 U. 3. 873; United States v. Martinez-Fuerte, 428 U. S. 543, the marginal contribution to roadway safety possibly resulting from a system of spot checks cannot justify subjecting every occupant of every vehicle on the roads to a seizure at the unbridled discretion of law enforcement officials. Pp. 440 U. S. 655-661.

(c) An individual operating or traveling in an automobile does not lose all reasonable expectation of privacy simply because the automobile and its use are subject to government regulation. People are not shorn of all Fourth Amendment protection when they step from their homes onto the public sidewalk; nor are they shorn of those interests when they step from the sidewalks into their automobiles. Pp. 440 U. S. 662-663.

(d) The holding in this case does not preclude Delaware or other States from developing methods for spot checks that involve less intrusion or that do not involve the unconstrained exercise of discretion. Questioning of all oncoming traffic at roadblock-type stops is one possible alternative. P. 440 U. S. 663.

382 A.2d 1359, affirmed.

WHITE, J., delivered the opinion of the Court, in which BURGER, C.J., and BRENNAN, STEWART, MARSHALL, BLACKMUN, POWELL, and STEVENS, JJ., joined. BLACKMUN, J., filed a concurring opinion, in which POWELL, J., joined, post, p. 440 U. S. 663. REHNQUIST, J., filed a dissenting opinion, post, p. 440 U. S. 664.

Page 440 U. S. 650