Ohio v. Robinette

The U.S. Supreme Court found that the Ohio Supreme Court did not find adequate and independent grounds apart from the U.S. Constitution to support its decision and its requirements for their police officers to practice a "first-tell-then-ask" rule. They emphasized that the ruling of the Ohio Supreme Court should have been based on the state law, rather than Federal constitutional law. In effect, the Court's rationale served as notice to state courts that the question of jurisdiction was largely determined by the rationale of cases and statutes cited. Reliance on federal statutes and federally adjudicated cases yielded a jurisdictional possibility for the U.S. Supreme Court to intervene.

The dissenting opinion held that continued detention was unlawful beyond the original purpose of detention, a traffic violation, once a traffic stop was complete. However, both majority and minority opinions concluded no requirements existed, under the Fourth Amendment, for police officers to notify drivers when they are "free to go." In differing with the dissenting opinion, the majority ruled that after a vehicle had been stopped, the motivation of a police officer did not have to preclude asking for voluntary consent to search. In such instances, under the "totality of circumstances," consent to search was obligatory, and therefore provisions of the Fourth Amendment did not require police officers to inform motorists that they could refuse additional communication because initial purpose for detention had finished.