The petitioner was convicted of armed robbery after a jury trial in the Superior Court of Los Angeles County, California. At the trial several articles which had been found by police officers in a search of the petitioner's hotel room during his absence were admitted into evidence over his objection. A District Court of Appeal of California affirmed the conviction, and the Supreme Court of California denied further review. We granted certiorari, limiting review 'to the question of whether evidence was admitted which had been obtained by an unlawful search and seizure.' 374 U.S. 826, 83 S.Ct. 1880, 10 L.Ed.2d 1050. For the reasons which follow, we conclude that the petitioner's conviction must be set aside.
The essential facts are not in dispute. On the night of October 25, 1960, the Budget Town Food Market in Monrovia, California, was robbed by two men, one of whom was described by eyewitnesses as carrying a gun and wearing hornrimmed glasses and a grey jacket. Soon after the robbery a checkbook belonging to the petitioner was found in an adjacent parking lot and turned over to the police. Two of the stubs in the checkbook indicated that checks had been drawn to the order of the Mayfair Hotel in Pomona, California. Pursuing this lead, the officers learned from the Police Department of Pomona that the petitioner had a previous criminal record, and they obtained from the Pomona police a photograph of the petitioner They showed the photograph to the two eyewitnesses to the robbery, who both stated that the picture looked like the man who had carried the gun. On the basis of this information the officers went to the Mayfair Hotel in Pomona at about 10 o'clock on the night of October 27. They had neither search nor arrest warrants. There then transpired the following events, as later recounted by one of the officers:
'We approached the desk, the night clerk, and asked him if there was a party by the name of Joey L. Stoner living at the hotel. He checked his records and stated 'Yes, there is.' And we asked him what room he was in. He stated he was in Room 404 but he was out at this time.
'We asked him how he knew that he was out. He stated that the hotel regulations required that the key to the room would be placed in the mail box each time they left the hotel. The key was in the mail box, that he therefore knew he was out of the room.
'We asked him if he would give us permission to enter the room, explaining our reasons for this.
'Q. What reasons did you explain to the clerk?
'A. We explained that we were there to make an arrest of a man who had possibly committed a robbery in the City of Monrovia, and that we were concerned about the fact that he had a weapon. He stated 'In this case, I will be more than happy to give you permission and I will take you directly to the room.'
'Q. Is that what the clerk told you?
'A. Yes, sir.
'Q. What else happened?
'A. We left one detective in the lobby, and Detective Oliver, Officer Collins, and myself, along with the night clerk, got on the elevator and proceeded to the fourth floor, and went to Room 404. The night clerk placed a key in the lock, unlocked the door, and says, 'Be my guest."
The officers entered and made a thorough search of the room and its contents. They found a pair of hornrimmed glasses and a grey jacket in the room, and a .45-caliber automatic pistol with a clip and several cartridges in the bottom of a bureau drawer. The petitioner was arrested two days later in Las Vegas, Nevada. He waived extradition and was returned to California for trial on the charge of armed robbery. The gun, the cartridges and clip, the horn-rimmed glasses, and the grey jacket were all used as evidence against him at his trial.
