Whether Mathiason was in custody, or otherwise deprived of his freedom of action in a significant way, when he made his initial unwarned admission.
Holding
No. Mathiason was not in custody for Miranda purposes during the interview.
Reasoning
Miranda governs custodial interrogation: questioning initiated by law enforcement after a person has been taken into custody or otherwise significantly deprived of freedom of action. The relevant inquiry was therefore whether the circumstances meaningfully restricted Mathiason's ability to leave, not whether the interview was uncomfortable or accusatory.
The undisputed facts showed no such restriction. Mathiason voluntarily came to the station after the officer asked to meet with him, was immediately told that he was not under arrest, and was not formally detained. At the end of the approximately half-hour interview, he in fact left the station without hindrance.
The Court distinguished earlier cases applying Miranda outside a traditional police-station arrest. In those cases, the suspect was already confined in prison or had been arrested in his home and was no longer free to go where he pleased. Mathiason, by contrast, was not subject to any comparable restraint on his movement.