Pennsylvania v. Muniz Case Brief

Why is the case important?

A police officer found two individuals in a car parked on the side of a highway. The officer thought he smelled alcohol on one of the individual’s breath and began sobriety tests.

Facts of the case

“On November 30, 1986, a patrol officer saw Inocencio Muniz and another passenger in a car stopped on the shoulder of a highway. When the officer approached, he could smell alcohol on Muniz’s breath and saw that his eyes were bloodshot and his face was flushed. The officer advised Muniz to remain parked, but as he was leaving he saw Muniz drive off. The officer pulled Muniz over and had him perform three field sobriety tests, all of which Muniz failed. Muniz told the officer he failed them because he had been drinking. The officer arrested Muniz and took him to a booking center, where he was told that his actions and voice were being recorded, but no one read him his Miranda rights. Muniz answered a series of questions about himself and stumbled over an answer regarding the year he turned six. Muniz again failed three field sobriety tests and refused a breathalyzer test. The officer then read Muniz his Miranda rights, and Muniz signed a statement waiving them. In subsequent questioning, he admitted to being under the influence of alcohol.At trial, the video and audio recordings of Muniz’s behavior at the booking center were admitted into evidence, along with the officer’s reports of Muniz’s failure of the field sobriety tests and his incriminating statements. Muniz was convicted of driving under the influence of alcohol. He filed a motion for a new trial and argued that the evidence of his behavior and statements prior to the Miranda warning should have been excluded from trial. The trial court denied the motion. The Superior Court of Pennsylvania reversed and held that the testimony regarding Muniz’s behavior and the results of the field sobriety tests was physical in nature, not testimonial, but that the audio portion of the recording should have been suppressed. The Pennsylvania Supreme Court denied the application for review.”


Whether various incriminating utterances of a drunken-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.


“The majority observed this case implicates both the ‘testimonial’ and ‘compulsion’ components of the privilege against self-incrimination in the context of pretrial questioning. Because Muniz was not advised of his Miranda rights until after the videotaped proceedings at the booking center were completed, any verbal statements that were both testimonial in nature and elicited during custodial interrogation should have been suppressed.
The majority agreed with the Commonwealth’s contention that Muniz’s answers are not rendered inadmissible by Miranda merely because the slurred nature of his speech was incriminating. The physical inability to articulate words in a clear manner due to ‘the lack of muscular coordination of his tongue and mouth, is not itself a testimonial component of Muniz’s responses to Officer Hosterman’s introductory questions.’ Any slurring of speech and other evidence of lack of muscular coordination revealed by Muniz’s responses to Officer Hosterman’s direct questions constitute nontestimonial components of those responses.
The majority then observed Muniz’s answer to the sixth birthday question was incriminating, not just because of his delivery, but also because of his answer’s content

  • the trier of fact could infer from Muniz’s answer (that he did not know the proper date) that his mental state was confused. Along the same lines the correct question for present purposes is whether the incriminating inference of mental confusion is drawn from a testimonial act or from physical evidence. Or in other words, the question is not whether a suspect’s ‘impaired mental faculties’ can fairly be characterized as an aspect of his physiology, but rather whether Muniz’s response to the sixth birthday question that gave rise to the inference of such an impairment was testimonial in nature.
    Whenever a suspect is asked for a response requiring him to communicate an express or implied assertion of fact or belief, the suspect confronts the trilemma of truth, falsity, or silence, and hence the response (whether based on truth or falsity) contains a testimonial component.
    The sixth birthday question in this case required a testimonial response. Therefore, because the Court concluded that Muniz’s response to the sixth birthday question was testimonial, the response should have been suppressed.
    The majority disagreed with the Commonwealth’s contention that Officer Hosterman’s first seven questions regarding Muniz’s name, address, height, weight, eye color, date of birth, and current age do not qualify as custodial interrogation as we defined the term in Innis, merely because the questions were not intended to elicit information for investigatory purposes. To the contrary, the majority concluded Muniz’s answers to these first seven questions are nonetheless admissible because the questions fall within a ‘routine booking question’ exception which exempts from Miranda’s coverage questions to secure the ‘biographical data necessary to complete booking or pretrial services.’ Further, the first seven questions asked at the booking center fall outside the protections of Miranda and the answers thereto need not be suppressed.
    Officer Hosterman’s dialogue with Muniz concerning the physical sobriety tests consisted primarily of carefully scripted instructions as to how the tests were to be performed. These instructions were not likely to be perceived as calling for any verbal response and therefore were not ‘words or actions’ constituting custodial interrogation, with two narrow exceptions not relevant here. The dialogue also contained limited and carefully worded inquiries as to whether Muniz understood those instructions, but these focused inquiries were necessarily ‘attendant to’ the police procedure held by the court to be legitimate. Hence, Muniz’s incriminating utterances during this phase of the videotaped proceedings were ‘voluntary’ in the sense that they were not elicited in response to custodial interrogation.
    The majority also concluded that Miranda does not require suppression of the statements Muniz made when asked to submit to a breathalyzer examination. Moreover, it believed that Muniz’s statements were not prompted by an interrogation within the meaning of Miranda, and therefore the absence of Miranda warnings does not require suppression of these statements at trial.”


    “The Supreme Court of the United States vacated the superior court’s judgment and remanded the case for further proceedings. The Court noted that the Miranda requirement afforded protection against self-incrimination to persons under custodial interrogation. The Court distinguished between testimonial and real or physical evidence when invoking the privilege. The Court held that a field sobriety test or taking a blood sample constituted real or physical evidence

  • whereas requiring Muniz to respond to specific questions was testimonial. Muniz’s Fifth Amendment rights were violated by the admission of that part of the videotape in which he responded to the question as to the date of his sixth birthday, but not by the admission of the parts of the videotape in which he performed the sobriety tests and refused to submit to the breathalyzer test. Thus, the superior court erred by suppressing the entire videotape.”
    • Case Brief: 1990
    • Petitioner: Pennsylvania
    • Respondent: Inocencio Muniz
    • Decided by: Rehnquist Court

    Citation: 496 US 582 (1990)
    Argued: Feb 27, 1990
    Decided: Jun 18, 1990