Facts of the Case

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.

Question

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

Conclusion

Yes. In an 8-to-1 decision, the Court held that the privacy interests of travelers outweighed the state interests in discretionary spot checks of automobiles. The Court found that random checks made only marginal contributions to roadway safety and compliance with registration requirements; less intrusive means could have been used to serve the same ends. Officers must be held to a "probable cause" standard for searches, otherwise individuals would be subject to "unfettered governmental intrusion" each time they entered an automobile.