Oregon v. Mathiason

Mathiason voluntarily met an officer at a state patrol office, was told he was not under arrest, was falsely informed his fingerprints were found at the scene, confessed within about five minutes, was then Mirandized and had his confession taped, and left the station 30 minutes after arriving without being arrested; the state supreme court found the interrogation environment coercive and suppressed the pre-warning confession's fruits.