Michigan Department of State Police v. Sitz
United States Supreme Court
496 U.S. 444 (1990)
The Michigan Department of State Police (defendant) set up sobriety checkpoints where every passing vehicle was briefly stopped and its driver checked for signs of intoxication; drivers who appeared sober were sent on immediately, with average stops lasting about 25 seconds, while those suspected of impairment underwent further testing and possible arrest. During one 75-minute operation, 126 vehicles passed through, two drivers were detained for further testing, and two were arrested for drunk driving. Sitz (plaintiff) sued the day before the checkpoint program began, seeking to enjoin it as an unreasonable seizure under the Fourth Amendment. The trial court and state appeals court agreed the checkpoints were unconstitutional.
Whether temporary sobriety checkpoints, which briefly stop and screen all passing motorists without individualized suspicion, are reasonable seizures under the Fourth Amendment.