Justice Brennan delivered the opinion of the Court, except as to Part III-C.
We must decide in this case whether various incriminating utterances of a drunk-driving suspect, made while performing a series of sobriety tests, constitute testimonial responses to custodial interrogation for purposes of the Self-Incrimination Clause of the Fifth Amendment.
- During the early morning hours of November 30, 1986, a patrol officer spotted respondent Inocencio Muniz and a passenger parked in a car on the shoulder of a highway. When the officer inquired whether Muniz needed assistance, Muniz replied that he had stopped the car so he could urinate. The officer smelled alcohol on Muniz's breath and observed that Muniz's eyes were glazed and bloodshot and his face was flushed. The officer then directed Muniz to remain parked until his condition improved, and Muniz gave assurances that he would do so. But as the officer returned to his vehicle, Muniz drove off. After the officer pursued Muniz down the highway and pulled him over, the officer asked Muniz to perform three standard field sobriety tests: a "horizontal gaze nystagmus" test, a "walk and turn" test, and a "one leg stand" test.[fn1] 1547 (1987), and explained that under the law his refusal to take the test would result in automatic suspension of his drivers' license for one year. Muniz asked a number of questions about the law, commenting in the process about his state of inebriation. Muniz ultimately refused to take the breath test. At this point, Muniz was for the first time advised of his Miranda rights. Muniz then signed a statement waiving his rights and admitted in response to further questioning that he had been driving while intoxicated.
Both the video and audio portions of the videotape were admitted into evidence at Muniz' bench trial,[fn2] " Id., at C6, quoting Commonwealth v. Benson, 280 Pa. Super. 20, 29, 421 A. 2d 383, 387 (1980).
On appeal, the Superior Court of Pennsylvania reversed. The appellate court agreed that when Muniz was asked "to submit to a field sobriety test, and later perform these tests before the videotape camera, no Miranda warnings were required" because such sobriety tests elicit physical rather than testimonial evidence within the meaning of the Fifth Amendment. 377 Pa. Super., at 387, 547 A. 2d, at 422. The court concluded, however, that "when the physical nature of the tests begins to yield testimonial and communicative statements ... the protections afforded by Miranda are invoked." Ibid. The court explained that Muniz's answer to the question regarding his sixth birthday and the statements and inquiries he made while performing the physical dexterity tests and discussing the breathalyzer test "are precisely the sort of testimonial evidence that we expressly protected in [previous cases]," id., at 390, 547 A. 2d at 423, because they "reveal[ed] his thought processes." Id., at 389, 547 A. 2d, at 423. The court further explained: "[N]one of Muniz's utterances were spontaneous, voluntary verbalizations. Rather, they were clearly compelled by the questions and instructions presented to him during his detention at the Booking Center. Since the ... responses and communications were elicited before Muniz received his Miranda warnings, they should have been excluded as evidence." Id., at 390, 547 A. 2d, at 423.[fn3] Concluding that the audio portion of the videotape should have been suppressed in its entirety, the court reversed Muniz's conviction and remanded the case for a new trial.[fn4][fn5] " 384 U.S., at 763. We also acknowledged that "both federal and state courts have usually held that it offers no protection against compulsion to submit to fingerprinting, photographing, or measurements, to write or speak for identification, to appear in court, to stand, to assume a stance, to walk, or to make a particular gesture." Id., at 764. Embracing this view of the privilege's contours, we held that "the privilege is a bar against compelling `communications' or `testimony,' but that compulsion which makes a suspect or accused the source of `real or physical evidence' does not violate it." Ibid. Using this "helpful framework for analysis," ibid., we held that a person suspected of driving while intoxicated could be forced to provide a blood sample, because that sample was "real or physical evidence" outside the scope of the privilege and the sample was obtained in manner by which "[p]etitioner's testimonial capacities were in no way implicated." Id., at 765.
We have since applied the distinction between "real or physical" and "testimonial" evidence in other contexts where the evidence could be produced only through some volitional act on the part of the suspect. In United States v. Wade, 388 U.S. 218 (1967), we held that a suspect could be compelled to participate in a lineup and to repeat a phrase provided by the police so that witnesses could view him and listen to his voice. We explained that requiring his presence and speech at a lineup reflected "compulsion of the accused to exhibit his physical characteristics, not compulsion to disclose any knowledge he might have." Id., at 222; see id., at 222-223 (suspect was "required to use his voice as an identifying physical characteristic"). In Gilbert v. California, 388 U.S. 263 (1967), we held that a suspect could be compelled to provide a handwriting exemplar, explaining that such an exemplar, "in contrast to the content of what is written, like the voice or body itself, is an identifying physical characteristic outside [the privilege's] protection." Id., at 266-267. And in United States v. Dionisio, 410 U.S. 1 (1973), we held that suspects could be compelled to read a transcript in order to provide a voice exemplar, explaining that the "voice recordings were to be used solely to measure the physical properties of the witnesses' voices, not for the testimonial or communicative content of what was to be said." Id., at 7.
Under Schmerber and its progeny, we agree with the Commonwealth that any slurring of speech and other evidence of lack of muscular coordination revealed by Muniz's responses to Officer Hosterman's direct questions constitute non testimonial components of those responses. Requiring a suspect to reveal the physical manner in which he articulates words, like requiring him to reveal the physical properties of the sound produced by his voice, see Dionisio, supra, does not, without more, compel him to provide a "testimonial" response for purposes of the privilege.