Schmerber v. California, 384 U.S. 757 (1966)
Schmerber v. California is a cornerstone of constitutional criminal procedure that defines how the Fourth and Fifth Amendments apply to compelled collection of bodily evidence.
Does the compelled, warrantless withdrawal and testing of a DUI suspect's blood, taken by medical personnel at a hospital over the suspect's objection, violate (1) the Fifth Amendment privilege against self-incrimination, (2) the Fourth Amendment prohibition against unreasonable searches and seizures, or (3) the Fourteenth Amendment guarantee of due process?
Fifth Amendment: The privilege against self-incrimination protects an accused from being compelled to provide testimonial or communicative evidence, not from being compelled to provide real or physical evidence. Compelling a blood sample is not testimonial. Fourth Amendment: A blood draw is a search subject to the Fourth Amendment. Warrantless searches are per se unreasonable unless they fall within a recognized exception, including exigent circumstances. Exigency may justify a warrantless blood draw when officers have probable cause to believe the suspect is intoxicated and the natural dissipation of alcohol in the bloodstream, combined with case-specific factors, makes securing a warrant impracticable. Even then, the procedure must be reasonable in scope and manner, meaning performed by trained medical personnel in a medically appropriate setting. Fourteenth Amendment: A compelled medical procedure violates due process only if it shocks the conscience or is conducted in a brutal, offensive, or medically unsafe manner; routine blood draws by medical staff do not meet that standard.
The Supreme Court affirmed the conviction. The compelled blood draw did not violate the Fifth Amendment because it produced physical, not testimonial, evidence. It did not violate the Fourth Amendment because, given probable cause and the exigency created by the natural dissipation of alcohol and the delays attendant to the accident and medical treatment, the warrantless blood draw was reasonable and properly conducted in a hospital by a physician. The procedure did not offend due process under the Fourteenth Amendment.
Schmerber is foundational in two respects. First, it cements the testimonial-versus-physical-evidence distinction for the Fifth Amendment, shaping later cases involving fingerprints, handwriting, voice exemplars, and lineups. Second, it frames the Fourth Amendment analysis for compelled bodily intrusions: they are searches that generally require a warrant unless the government proves exigent circumstances and medical reasonableness. The decision also makes clear that search-incident-to-arrest doctrine does not automatically authorize bodily intrusions. For law students, Schmerber is the starting point for any question about bodily evidence and DUI enforcement. Subsequent cases refine its contours: Winston v. Lee (1985) applied heightened scrutiny to surgical intrusions; Missouri v. McNeely (2013) rejected a categorical rule that alcohol dissipation alone creates exigency, requiring a case-by-case evaluation; Birchfield v. North Dakota (2016) distinguished breath tests (often permissible incident to arrest) from blood tests (more intrusive, generally requiring a warrant or valid exception); and Mitchell v. Wisconsin (2019) addressed unconscious drivers. Together, these cases build on Schmerber's core principles while narrowing when warrantless blood draws are reasonable.