US Supreme Court requires warrant before taking of blood in DWI Missouri v McNeely

US Supreme Court requires warrant before taking of blood in DWI Missouri v McNeely 133 S. Ct. 1552 (2013)

Respondent McNeely was stopped by a Missouri police officer for speeding and crossing the centerline. After declining to take a breath test to measure his blood alcohol concentration (BAC), he was arrested and taken to a nearby hospital for blood testing. The officer never attempted to secure a search warrant. McNeely refused to consent to the blood test, but the officer directed a lab technician to take a sample. McNeely's BAC tested well above the legal limit, and he was charged with driving while intoxicated (DWI). He moved to suppress the blood test result, arguing that taking his blood without a warrant violated his Fourth Amendment rights. The trial court agreed, concluding that the exigency exception to the warrant requirement did not apply because, apart from the fact that McNeely's blood alcohol was dissipating, no circumstances suggested that the officer faced an emergency. The State Supreme Court affirmed, relying on Schmerber v. California, 384 U. S. 757, in which this Court upheld a DWI suspect's warrantless blood test where the officer "might reasonably have believed that he was confronted with an emergency, in which the delay necessary to obtain a warrant, under the circumstances, threatened 'the destruction of evidence,' " id., at 770. This case, the state court found, involved a routine DWI investigation where no factors other than the natural dissipation of blood alcohol suggested that there was an emergency, and, thus, the nonconsensual warrantless test violated McNeely's right to be free from unreasonable searches of his person.

Held: The judgment is affirmed.  

Justice Sotomayor delivered the opinion of the Court with respect to Parts I, II--A, II--B, and IV, concluding that in drunk-driving investigations, the natural dissipation of alcohol in the bloodstream does not constitute an exigency in every case sufficient to justify conducting a blood test without a warrant.  

(a) The principle that a warrantless search of the person is reasonable only if it falls within a recognized exception, see, e.g., United States v. Robinson, 414 U. S. 218, applies here, where the search involved a compelled physical intrusion beneath McNeely's skin and into his veins to obtain a blood sample to use as evidence in a criminal investigation. One recognized exception "applies when ' "the exigencies of the situation" make the needs of law enforcement so compelling that [a] warrantless search is objectively reasonable.' " Kentucky v. King, 563 U. S.. This Court looks to the totality of circumstances in determining whether an exigency exits. See Brigham City v. Stuart, 547 U. S. 398. Applying this approach in Schmerber, the Court found a warrantless blood test reasonable after considering all of the facts and circumstances of that case and carefully basing its holding on those specific facts, including that alcohol levels decline after drinking stops and that testing was delayed while officers transported the injured suspect to the hospital and investigated the accident scene.  

(b) The State nonetheless seeks a per se rule, contending that exigent circumstances necessarily exist when an officer has probable cause to believe a person has been driving under the influence of alcohol because BAC evidence is inherently evanescent. Though a person's blood alcohol level declines until the alcohol is eliminated, it does not follow that the Court should depart from careful case-by-case assessment of exigency. When officers in drunk-driving investigations can reasonably obtain a warrant before having a blood sample drawn without significantly undermining the efficacy of the search, the Fourth Amendment mandates that they do so. See McDonald v. United States, 335 U. S. 451. Circumstances may make obtaining a warrant impractical such that the alcohol's dissipation will support an exigency, but that is a reason to decide each case on its facts, as in Schmerber, not to accept the "considerable overgeneralization" that a per se rule would reflect, Richards v. Wisconsin, 520 U. S. 385. Blood testing is different in critical respects from other destruction-of-evidence cases.