Pennsylvania v. Muniz
Citation and Court
496 U.S. 582 (1990) — Supreme Court of the United States
Facts
Muniz was arrested for DUI. At the police station, without Miranda warnings, officers asked him routine booking questions and also asked him to recite the alphabet and perform sobriety tests. His slurred speech and confused answers were recorded on video and used at trial. He argued the statements violated the Fifth Amendment.
Issue
Whether routine booking questions and responses — including slurred speech during DUI sobriety testing — are protected by the Fifth Amendment privilege against self-incrimination.
Holding
Slurred speech and non-verbal conduct during sobriety tests are not testimonial and therefore not protected by the Fifth Amendment; routine booking questions (name, address, date of birth) are covered by a booking exception to Miranda and are admissible; but a question requiring a specific mental calculation (Muniz’s sixth birthday question) was testimonial and required Miranda warnings.
Rule / Doctrine
The Fifth Amendment protects only testimonial communications — those that reveal the contents of the mind. Physical characteristics (slurred speech, inability to walk a line) are non-testimonial. Routine booking information is excepted from Miranda because it is not designed to elicit incriminating responses. But a question requiring the suspect to think and answer from memory is testimonial, even if the incrimination comes from inability to answer rather than content.
Significance
Clarified the testimonial/non-testimonial distinction for DUI evidence, established a booking exception to Miranda, and highlighted that the Fifth Amendment turns on whether the government is compelling a disclosure of the mind’s contents.