In Dunaway v. New York, the U.S Supreme Court ruled that police detention of a suspect without probable cause for arrest violated the Fourth Amendment's protection against unreasonable seizures and searches. The case involved Robert Dunaway who was suspected in a robbery-homicide case but with no substantial evidence linking him to the crime. Police detained him, read his Miranda rights, interrogated him at the station where he confessed to committing murder. His confession led to his conviction which he appealed on grounds that it was obtained through illegal detention violating his constitutional rights. The court agreed with Dunaway stating that such detentions were indistinguishable from traditional arrests which require probable cause as per Fourth Amendment standards.

In the dissenting opinion for Dunaway v. New York, Justice White argued that the majority's decision was inconsistent with previous rulings and overly restrictive on police procedures. He contended that there were reasonable grounds to detain Dunaway based on a reliable tip from an informant, even though it might not have been enough to justify an arrest warrant. The detention led to a confession which should be admissible as evidence in court according to him. Furthermore, he pointed out that if every detention required probable cause then many common police practices would become illegal such as traffic stops or questioning witnesses at crime scenes without concrete proof of their involvement in the crime. Therefore, he believed this ruling could potentially hinder effective law enforcement.