In a plurality opinion, the United States Supreme Court recently held, in the opinion entitled Mitchell v. Wisconsin[1], that the exigent circumstances exception to the warrant requirement of the Fourth Amendment will usually permit a blood draw from an unconscious drunk-driver suspect to secure blood alcohol content evidence.


In May 2013, Sheboygan Police Department Officer Alexander Jaeger received a report that an apparently very drunk Gerald Mitchell had gotten into a van and then driven away. Officer Jaeger soon found Mitchell stumbling on foot near a lake. Mitchell’s speech was slurred and he could barely stand. Officer Jaeger thought a field sobriety test could be dangerous to Mitchell in his condition, so Officer Jaeger gave Mitchell a preliminary breath test. The breath test registered a blood alcohol concentration (BAC) level of 0.24%, which is three times Wisconsin’s legal limit for driving. Officer Jaeger arrested Mitchell for operating a vehicle while intoxicated. Following a standard practice, Officer Jaeger drove him to a police station for a more reliable breath test using evidence-grade equipment.

By the time they arrived at the station, however, Mitchell was too lethargic even for the breath test. Jaeger drove Mitchell to a nearby hospital for a blood test, but Mitchell lost consciousness on the way there and had to be wheeled in. Despite Mitchell’s unconscious state, Officer Jaeger read aloud to Mitchell the standard statement giving drivers a chance to refuse BAC testing. Hearing no response, Jaeger asked hospital staff to draw a blood sample, under a state law (Wis. Stat. section 343.305 (2016)) that presumes that a person incapable of withdrawing implied consent to BAC testing has not done so. At about 90 minutes after his arrest, Mitchell’s BAC was registered at 0.222%, well above the legal limit even then.

Mitchell was charged with violating two drunk-driving laws. He moved to suppress the results of the blood test on the ground that it violated his Fourth Amendment right against unreasonable searches because it was conducted without a warrant. The trial court denied Mitchell’s motion, and a jury found Mitchell guilty of the charged offenses. An intermediate appellate court certified two questions to the Wisconsin Supreme Court: first, whether compliance with the State’s implied-consent law was sufficient to show that Mitchell’s test was consistent with the Fourth Amendment and, second, whether a warrantless blood draw from an unconscious person violates the Fourth Amendment. The Wisconsin Supreme Court affirmed the lawfulness of Mitchell’s blood test. Mitchell petitioned for a writ of certiorari.


The United States Supreme Court granted certiorari to decide whether a statute authorizing a blood draw from an unconscious motorist provides an exception to the Fourth Amendment warrant requirement.

The Court explained that all States have laws that prohibit motorists from driving with a BAC that exceeds a specified level, and all States have passed corresponding implied-consent laws. Under implied-consent laws, in exchange for the privilege of using the public roads, drivers are required to submit to BAC testing when there is sufficient reason to believe they are violating the State’s drunk-driving laws.

Under Wisconsin’s Section 343.305, drivers are presumed to have consented to breath or blood tests if an officer has reason to believe they have committed one of several drug- or alcohol-related offenses. An officer intending to administer a BAC test must read aloud a statement declaring the intent to conduct the test and informing drivers of their options and the implications of their choice. A test will not be administered if a driver refuses the test and thereby “withdraws” his statutorily presumed consent. However, “[a] person who is unconscious or otherwise not capable of withdrawing consent is presumed not to have withdrawn consent.” (Section 343.305(3)(b).)

The Court explained that, under the Fourth Amendment, the “right of the people to be secure in their persons . . . against unreasonable searches” is protected and “no Warrants shall issue, but upon probable cause.” The Court noted that a blood draw is a search of the person for Fourth Amendment purposes, and that a warrant is normally required for a lawful search. However, the Supreme Court has also “made it clear that there are exceptions to the warrant requirement.” Illinois v. McArthur, 531 U. S. 326, 330 (2001). The “exigent circumstances” exception allows warrantless searches “to prevent the imminent destruction of evidence.” Missouri v. McNeely, 569 U. S. 141, 149 (2013). More specifically, a warrantless search is permitted under the exigent circumstances exception when “‘there is compelling need for official action and no time to secure a warrant.’” McNeely, supra, at 149, (quoting Michigan v. Tyler, 436 U. S. 499, 509 (1978)).

The Court noted that a standard evidence-grade breath test is typically conducted after a motorist is transported to a police station or a related facility where such equipment is kept. The Court also noted that Mitchell’s stupor and eventual unconsciousness denied officials a reasonable opportunity to administer an evidence-grade breath test. Within this context, the Court considered (1) whether the need for a blood test is compelling, and, if so, (2) whether such “compelling need” justifies a warrantless search because there is “no time to secure a warrant.” If both elements were met in the unconscious drunk driver context, the exigent circumstances exception applies.

The Court first determined that BAC testing is a “compelling need.” The Court explained that courts have long understood that highway safety is a vital, “compelling,” and “paramount” public interest,[2] adding that domestic alcohol-related accidents between 1982 and 2016 resulted in between 10,000 and 20,000 deaths annually. The Court added that with regard to promoting highway safety, state and federal legislators have long believed, backed by persuasive data, that legal limits on a driver’s BAC have a major impact in dramatically reducing highway deaths and injuries. The Court also explained that enforcing legal BAC limits requires a test accurate enough to hold up in court,[3] and “[e]xtraction of blood samples for testing is a highly effective means of” measuring “the influence of alcohol.” Schmerber v. California, 384 U. S. 757, 771 (1966). Moreover, because alcohol naturally dissipates “by the minute”[4] from the bloodstream, enforcement of BAC testing requires prompt testing to properly and accurately obtain BAC evidence. Lastly, when a breath test is unavailable (as in the case of unconscious drivers who cannot exhale into a breathalyzer) to promote those interests, “a blood draw becomes necessary.” McNeely, 569 U. S., at 170 (opinion of Roberts, C. J.). The Court therefore found that there clearly is a “compelling need” for a blood test of drunk-driving suspects whose condition deprives officials of a reasonable opportunity to conduct a breath test.

The Supreme Court then turned to the remaining exigency element, i.e. whether the compelling need justifies a warrantless search because there is “no time to secure a warrant.” In Schmerber v. California, the dissipation of BAC justified a blood test of a drunk driver whose accident gave police other pressing duties, because the additional delay that would have been caused by obtaining a warrant application would have threatened the destruction of evidence. Thus, under Schmerber, exigency exists when (1) BAC evidence is dissipating and (2) some extra factor creates pressing health, safety, or law enforcement needs that would take priority over a warrant application.

The Court observed that in Schmerber, the car accident was the extra factor. For the issue here, the Court explained that it is the drunk driver’s unconsciousness that not only creates pressing needs, but also is itself a medical emergency. The suspect must be promptly taken to a hospital or other facility for urgent medical care, and immediate medical treatment could delay or distort a blood draw conducted later after the securing of a warrant, and so reduce its evidentiary value. In such a situation, as in Schmerber, an officer could “reasonably have believed that he was confronted with an emergency.” 384 U.S., at 771.

The Court also explained that in many unconscious-driver cases, the exigency would be “especially acute” because a driver drunk enough to lose consciousness would probably crash, giving officers many additional urgent tasks distinct from securing medical care for the suspect—tasks that would require them to put off applying for a warrant. Forcing police to put off other urgent tasks for even a relatively short period of time, the Court explained, could have tragic collateral costs.

Based upon the foregoing analysis, the Court held that “[w]hen police have probable cause to believe a person has committed a drunk-driving offense and the driver’s unconsciousness or stupor requires him to be taken to the hospital or similar facility before police have a reasonable opportunity to administer a standard evidentiary breath test, they may almost always order a warrantless blood test to measure the driver’s BAC without offending the Fourth Amendment.”

Accordingly, the United States Supreme Court vacated the judgment of the Wisconsin Supreme Court. The Court also remanded the case to provide Mitchell with the opportunity to demonstrate that his was an unusual case, in which his blood would not have been drawn had the police not been seeking BAC information and the police could not have reasonably asserted that a warrant application would interfere with other pressing needs or duties.

Dissenting and Concurring Opinions

Justice Thomas proposed a per se rule that “the natural metabolization of alcohol in the blood stream ‘creates an exigency once police have probable cause to believe the driver is drunk,’ regardless of whether the driver is conscious.” He concurred in the judgment only.

Justice Sotomayor, joined by Justices Ginsburg and Kagan, maintained that the Fourth Amendment warrant protections sufficed by requiring police officers seeking to draw blood from a person suspected of drunk driving to get a warrant if possible. That rule, said these justices, sufficed to resolve this case. This dissent found it appropriate that “the police bear a heavy burden” to justify a warrantless search like the one here based on “urgent need.”[5] However, the plurality, “acting entirely on its own freewheeling instincts – with no briefing or decision below on the question — …permits officers to order a blood draw of an unconscious person in all but the rarest cases, even when there is ample time to obtain a warrant.” The dissent found the plurality’s holding struck “another needless blow at the protections guaranteed by the Fourth Amendment.”

Justice Gorsuch disagreed, in a dissenting opinion, with the plurality’s use of this case to apply the exigent circumstances doctrine. He said such application posed complex and difficult questions that neither the parties nor the courts below discussed.


In Birchfield v. North Dakota, 136 S. Ct. 2160 (2016), the Supreme Court held that drunk-driving suspects’ arrests, taken alone, justify warrantless breath tests, but not blood tests. That case involved the use of the “search-incident-to-arrest” exception to BAC testing of conscious drunk-driving suspects. Here, the Supreme Court addressed unconscious drunk drivers, and held the exigent circumstances exception generally applied to permit a warrantless blood draw because the need for a blood test is compelling, and an officer’s duty to attend to more pressing needs may leave no time to seek a warrant.

Agencies should consider the distinction between the two contexts, and in their holdings. This case generally frees officers from choosing “between prioritizing a warrant application, to the detriment of critical health and safety needs, and delaying the warrant application, and thus the BAC test, to the detriment of its evidentiary value and all the compelling interests served by BAC limits.” However, it should be noted that the Court remanded the case to permit Mitchell, the criminal defendant, to establish that it was unnecessary to draw his blood for non-evidentiary purposes and that the officers would not have been delayed from performing other necessary duties.  In sum, the exigent circumstances exception to the Fourth Amendment’s warrant requirement will generally, but not always, permit a warrantless blood draw from an unconscious driver suspected of driving drunk.

As always, if you wish to discuss this matter in greater detail, please feel free to contact James R. Touchstone at (714) 446–1400 or via email at jrt@jones-mayer.com.

Information on www.jones-mayer.com is for general use and is not legal advice. The mailing of this Client Alert Memorandum is not intended to create, and receipt of it does not constitute, an attorney-client-relationship.

[1] 2019 U.S. LEXIS 4400 (U.S. June 27, 2019).

[2] Mackey v. Montrym, 443 U. S. 1, 17, 19 (1979).

[3] See Birchfield v. North Dakota, 136 S. Ct. 2160 (slip op., at 3-5) (2016), discussed in Client Alert Vol. 31 No. 11. Note that in Birchfield, the Supreme Court left as an exception to the warrant requirement those instances where an exigency may weigh in favor of a blood test without a search warrant. And Birchfield observed that Schmerber held that drunk driving may present such an exigency.

[4] McNeely, 569 U. S., at 169.

[5] Welsh v. Wisconsin, 466 U. S. 740, 749-750 (1984).