During a narcotics raid on petitioner's apartment by an undercover police officer and several plainclothes policemen, the undercover officer was shot and killed, and petitioner was wounded, as were two other persons in the apartment. Other than looking for victims of the shooting and arranging for medical assistance, the narcotics agents, pursuant to a police department directive that police officers should not investigate incidents in which they are involved, made no further investigation. Shortly thereafter, however, homicide detectives arrived on the scene to take charge of the investigation, and they proceeded to conduct an exhaustive four-day warrantless search of the apartment, which included the opening of dresser drawers, the ripping up of carpets, and the seizure of 200 to 300 objects. In the evening of the same day as the raid, one of the detectives went to the hospital where petitioner was confined in the intensive-care unit, and, after giving him Miranda warnings, persisted in interrogating him while he was lying in bed barely conscious, encumbered by tubes, needles, and a breathing apparatus, and despite the fact that he repeatedly asked that the interrogation stop until he could get a lawyer. Subsequently, petitioner was indicted for, and convicted of, murder, assault, and narcotics offenses. At his trial in an Arizona court, during which much of the evidence introduced against him was the product of the four-day search, and on appeal, petitioner contended that the evidence used against him had been unlawfully seized from his apartment without a warrant and that statements obtained from him at the hospital, used to impeach his credibility, were inadmissible because they had not been made voluntarily. The Arizona Supreme Court reversed the murder and assault convictions on state-law grounds, but affirmed the narcotics convictions, holding that the warrantless search of a homicide scene is permissible under the Fourth and Fourteenth Amendments and that petitioner's statements in the hospital were voluntary. Held:
1. The "murder scene exception" created by the Arizona Supreme Court to the warrant requirement is inconsistent with the Fourth and Fourteenth Amendments, and the warrantless search of petitioner's apartment was not constitutionally permissible simply because a homicide had occurred there. Pp. 388-395.
(a) The search cannot be justified on the ground that no constitutionally protected right of privacy was invaded, it being one thing to say that one who is legally taken into police custody has a lessened right of privacy in his person, and quite another to argue that he also has a lessened right of privacy in his entire house. Pp. 391-392.
(b) Nor can the search be justified on the ground that a possible homicide inevitably presents an emergency situation, especially since there was no emergency threatening life or limb, all persons in the apartment having been located before the search began. Pp. 392-393.
(c) The seriousness of the offense under investigation did not itself create exigent circumstances of the kind that under the Fourth Amendment justify a warrantless search, where there is no indication that evidence would be lost, destroyed, or removed during the time required to obtain a search warrant and there is no suggestion that a warrant could not easily and conveniently have been obtained. Pp. 393-394.
(d) The Arizona Supreme Court's guidelines for the "murder scene exception" did not afford sufficient protection to a person in whose home a homicide or assault occurs, where they conferred unbridled discretion upon the individual officer to interpret such terms as "reasonable . . . search," "serious personal injury with likelihood of death where there is reason to suspect foul play," and "reasonable period," it being this kind of judgmental assessment of the reasonableness and scope of a proposed search that the Fourth Amendment requires be made by a neutral and objective magistrate, not a police officer. Pp. 394-395.
2. Due process requires that the statements obtained from petitioner in the hospital not be used in any way against him at his trial, where it is apparent from the record that they were not "the product of his free and rational choice," Greenwald v. Wisconsin, 390 U.S. 519, 521, but to the contrary that he wanted not to answer his interrogator, and that while he was weakened by pain and shock, isolated from family, friends, and legal counsel, and barely conscious, his will was simply overborne. While statements made by a defendant in circumstances violating the strictures of Miranda v. Arizona, 384 U.S. 436, are admissible for impeachment if their "trustworthiness . . . satisfies legal standards," Harris v. New York, 401 U.S. 222, 224; Oregon v. Hass, 420 U.S. 714, 722, any criminal trial use against a defendant of his involuntary statement is a denial of due process of law. Pp. 396-402.115 Ariz. 472, 566 P.2d 273, reversed and remanded.