Checkpoint Cases

Delaware v Prouse: Law enforcement may not stop a motorist without reasonable suspicion only to check the status of a driver's license or ID unless the stop is made at a stationary enforcement or inspection checkpoint.

Michigan Department of State Police v. Sitz: A sobriety or license checkpoint is considered constitutional so long as all vehicles travelling through the checkpoint are stopped and checked. Motorists shall not be compelled to answer questions or provide biological samples without law enforcement having first detected signs of intoxication thereby granting them reasonable suspicion or probable cause to further detain the driver on real suspicion of intoxication.

United States v Martinez: Inland Border Patrol and Immigration Enforcement checkpoints are permitted on public roads.