Missouri v. McNeely

569 U.S. _

Case Year: 2013

Case Ruling: 8-1, Affirmed

Opinion Justice: Sotomayor

More Information

Concurring Opinions

Dissenting Opinions

Court Opinion Joiner(s):

Alito, Breyer, Ginsburg, Kagan, Kennedy, Roberts, Scalia


1st Concurring Opinion

Author: Kennedy


1st Dissenting Opinion

Author: Thomas


2nd Concurring Opinion

Author: Roberts


2nd Dissenting Opinion



3rd Concurring Opinion



3rd Dissenting Opinion



Other Concurring Opinions:


A Missouri police officer stopped Tyler McNeely’s truck at 2:08 a.m. after observing it exceeding the posted speed limit and repeatedly crossing the center line. The officer noticed McNeely’s bloodshot eyes, his slurred speech, and a smell of alcohol on his breath. He admitted to having had “a couple of beers.” McNeely performed poorly on a battery of field sobriety tests, and he declined to take a Breathalyzer test.

The officer placed McNeely under arrest and began to take him to the stationhouse. When McNeely indicated he would again refuse to give a breath sample for testing, the officer took him instead to a nearby hospital for a blood alcohol test. The officer explained to McNeely that under Missouri’s implied consent law, refusal to submit voluntarily to the blood test would lead to an immediate one-year suspension of his driver’s license and could be used against him in any future prosecution. When McNeely refused to consent to the blood draw, the officer directed a hospital technician to take a blood sample. Testing of the blood indicated that McNeely’s blood alcohol level was significantly above the legal limit. The blood draw took place at 2:35 a.m.

After being charged with driving under the influence of alcohol, McNeely challenged the blood test evidence claiming that the officer should have obtained a search warrant before ordering that a blood sample be taken. Missouri courts agreed, holding that the facts in the case did not establish sufficient exigent circumstances to exempt the officer from obtaining a warrant.

The Supreme Court agreed to review the case in order to resolve a single question: Does the natural dissipation of alcohol in the bloodstream establish an exigency that suffices on its own to justify an exception to the warrant requirement for nonconsensual blood testing in all drunk-driving investigations?



The Fourth Amendment provides in relevant part that “[t]he right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures, shall not be violated, and no Warrants shall issue, but upon probable cause.” Our cases have held that a warrantless search of the person is reasonable only if it falls within a recognized exception. United States v. Robinson (1973). That principle applies to the type of search at issue in this case, which involved a compelled physical intrusion beneath McNeely’s skin and into his veins to obtain a sample of his blood for use as evidence in a criminal investigation. Such an invasion of bodily integrity implicates an individual’s “most personal and deep-rooted expectations of privacy.” Winston v. Lee (1985).

We first considered the Fourth Amendment restrictions on such searches in Schmerber [v. California, 1966], where, as in this case, a blood sample was drawn from a defendant suspected of driving while under the influence of alcohol. Noting that “[s]earch warrants are ordinarily required for searches of dwellings,” we reasoned that “absent an emergency, no less could be required where intrusions into the human body are concerned,” even when the search was conducted following a lawful arrest. We explained that the importance of requiring authorization by a “neutral and detached magistrate” before allowing a law enforcement officer to “invade another’s body in search of evidence of guilt is indisputable and great.”

As noted, the warrant requirement is subject to exceptions. “One well-recognized exception,” and the one at issue in this case, “applies when the exigencies of the situation make the needs of law enforcement so compelling that a warrantless search is objectively reasonable under the Fourth Amendment.” Kentucky v. King (2011). . . . As is relevant here, we have . . . recognized that in some circumstances law enforcement officers may conduct a search without a warrant to prevent the imminent destruction of evidence. Cupp v. Murphy (1973). . . .

To determine whether a law enforcement officer faced an emergency that justified acting without a warrant, this Court looks to the totality of circumstances. . .

Our decision in Schmerber applied this totality of the circumstances approach. In that case, the petitioner had suffered injuries in an automobile accident and was taken to the hospital. While he was there receiving treatment, a police officer arrested the petitioner for driving while under the influence of alcohol and ordered a blood test over his objection. After explaining that the warrant requirement applied generally to searches that intrude into the human body, we concluded that the warrantless blood test “in the present case” was nonetheless permissible because 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.”

In support of that conclusion, we observed that evidence could have been lost because “the percentage of alcohol in the blood begins to diminish shortly after drinking stops, as the body functions to eliminate it from the system.” We added that “[p]articularly in a case such as this, where time had to be taken to bring the accused to a hospital and to investigate the scene of the accident, there was no time to seek out a magistrate and secure a warrant.” “Given these special facts,” we found that it was appropriate for the police to act without a warrant. We further held that the blood test at issue was a reasonable way to recover the evidence because it was highly effective, “involve[d] virtually no risk, trauma, or pain,” and was conducted in a reasonable fashion “by a physician in a hospital environment according to accepted medical practices.” And in conclusion, we noted that our judgment that there had been no Fourth Amendment violation was strictly based “on the facts of the present record.”

Thus, our analysis in Schmerber fits comfortably within our case law applying the exigent circumstances exception. In finding the warrantless blood test reasonable in Schmerber, we considered all of the facts and circumstances of the particular case and carefully based our holding on those specific facts.

The State properly recognizes that the reasonableness of a warrantless search under the exigency exception to the warrant requirement must be evaluated based on the totality of the circumstances. But the State nevertheless seeks a per se rule for blood testing in drunk-driving cases. The State contends that whenever an officer has probable cause to believe an individual has been driving under the influence of alcohol, exigent circumstances will necessarily exist because BAC [blood alcohol content] evidence is inherently evanescent. As a result, the State claims that so long as the officer has probable cause and the blood test is conducted in a reasonable manner, it is categorically reasonable for law enforcement to obtain the blood sample without a warrant.

It is true that as a result of the human body’s natural metabolic processes, the alcohol level in a person’s blood begins to dissipate once the alcohol is fully absorbed and continues to decline until the alcohol is eliminated. . . . Regardless of the exact elimination rate, it is sufficient for our purposes to note that because an individual’s alcohol level gradually declines soon after he stops drinking, a significant delay in testing will negatively affect the probative value of the results. This fact was essential to our holding in Schmerber. . . .

But it does not follow that we should depart from careful case-by-case assessment of exigency and adopt the categorical rule proposed by the State and its amici. In those drunk-driving investigations where police officers can reasonably obtain a warrant before a blood sample can be drawn without significantly undermining the efficacy of the search, the Fourth Amendment mandates that they do so. We do not doubt that some circumstances will make obtaining a warrant impractical such that the dissipation of alcohol from the bloodstream will support an exigency justifying a properly conducted warrantless blood test. That, however, is a reason to decide each case on its facts, as we did in Schmerber, not to accept the “considerable overgeneralization” that a per se rule would reflect.

. . . BAC evidence from a drunk-driving suspect naturally dissipates over time in a gradual and relatively predictable manner. Moreover, because a police officer must typically transport a drunk-driving suspect to a medical facility and obtain the assistance of someone with appropriate medical training before conducting a blood test, some delay between the time of the arrest or accident and the time of the test is inevitable regardless of whether police officers are required to obtain a warrant. This reality undermines the force of the State’s contention, endorsed by the dissent, that we should recognize a categorical exception to the warrant requirement because BAC evidence “is actively being destroyed with every minute that passes.” Consider, for example, a situation in which the warrant process will not significantly increase the delay before the blood test is conducted because an officer can take steps to secure a warrant while the suspect is being transported to a medical facility by another officer. In such a circumstance, there would be no plausible justification for an exception to the warrant requirement.

The State’s proposed per se rule also fails to account for advances in the 47 years since Schmerber was decided that allow for the more expeditious processing of warrant applications, particularly in contexts like drunk-driving investigations where the evidence offered to establish probable cause is simple. The Federal Rules of Criminal Procedure were amended in 1977 to permit federal magistrate judges to issue a warrant based on sworn testimony communicated by telephone. As amended, the law now allows a federal magistrate judge to consider “information communicated by telephone or other reliable electronic means.” States have also innovated. Well over a majority of States allow police officers or prosecutors to apply for search warrants remotely through various means, including telephonic or radio communication, electronic communication such as e-mail, and video conferencing. . . .

Of course, there are important countervailing concerns. While experts can work backwards from the BAC at the time the sample was taken to determine the BAC at the time of the alleged offense, longer intervals may raise questions about the accuracy of the calculation. For that reason, exigent circumstances justifying a warrantless blood sample may arise in the regular course of law enforcement due to delays from the warrant application process. But adopting the State’s per se approach would improperly ignore the current and future technological developments in warrant procedures, and might well diminish the incentive for jurisdictions “to pursue progressive approaches to warrant acquisition that preserve the protections afforded by the warrant while meeting the legitimate interests of law enforcement.”

In short, while the natural dissipation of alcohol in the blood may support a finding of exigency in a specific case, as it did in Schmerber, it does not do so categorically. Whether a warrantless blood test of a drunk-driving suspect is reasonable must be determined case by case based on the totality of the circumstances.

In an opinion concurring in part and dissenting in part, The Chief Justice agrees that the State’s proposed per se rule is overbroad . . . [but] then goes on to suggest his own categorical rule under which a warrantless blood draw is permissible if the officer could not secure a warrant (or reasonably believed he could not secure a warrant) in the time it takes to transport the suspect to a hospital or similar facility and obtain medical assistance. Although we agree that delay inherent to the blood-testing process is relevant to evaluating exigency, we decline to substitute The Chief Justice’s modified per se rule for our traditional totality of the circumstances analysis. . . .

The State and several of its amici, including the United States, express concern that a case-by-case approach to exigency will not provide adequate guidance to law enforcement officers deciding whether to conduct a blood test of a drunk-driving suspect without a warrant. The Chief Justice and the dissent also raise this concern. While the desire for a bright-line rule is understandable, the Fourth Amendment will not tolerate adoption of an overly broad categorical approach that would dilute the warrant requirement in a context where significant privacy interests are at stake. Moreover, a case-by-case approach is hardly unique within our Fourth Amendment jurisprudence. Numerous police actions are judged based on fact-intensive, totality of the circumstances analyses rather than according to categorical rules, including in situations that are more likely to require police officers to make difficult split-second judgments. As in those contexts, we see no valid substitute for careful case-by-case evaluation of reasonableness here. . . .

Because this case was argued on the broad proposition that drunk-driving cases present a per se exigency, the arguments and the record do not provide the Court with an adequate analytic framework for a detailed discussion of all the relevant factors that can be taken into account in determining the reasonableness of acting without a warrant. . . .

We hold 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.

  The judgment of the Missouri Supreme Court is affirmed.

  It is so ordered.


As the opinion of the Court is correct to note, the instant case, by reason of the way in which it was presented and decided in the state courts, does not provide a framework where it is prudent to hold any more than that always dispensing with a warrant for a blood test when a driver is arrested for being under the influence of alcohol is inconsistent with the Fourth Amendment.


A police officer reading this Court’s opinion would have no idea—no idea—what the Fourth Amendment requires of him, once he decides to obtain a blood sample from a drunk driving suspect who has refused a breathalyzer test. I have no quarrel with the Court’s “totality of the circumstances” approach as a general matter; that is what our cases require. But the circumstances in drunk driving cases are often typical, and the Court should be able to offer guidance on how police should handle cases like the one before us.

In my view, the proper rule is straightforward. Our cases establish that there is an exigent circumstances exception to the warrant requirement. That exception applies when there is a compelling need to prevent the imminent destruction of important evidence, and there is no time to obtain a warrant. The natural dissipation of alcohol in the bloodstream constitutes not only the imminent but ongoing destruction of critical evidence. That would qualify as an exigent circumstance, except that there may be time to secure a warrant before blood can be drawn. If there is, an officer must seek a warrant. If an officer could reasonably conclude that there is not, the exigent circumstances exception applies by its terms, and the blood may be drawn without a warrant. . . .

The Court resists the foregoing, contending that the question presented somehow inhibits such a focused analysis in this case. It does not. The question presented is whether a warrantless blood draw is permissible under the Fourth Amendment “based upon the natural dissipation of alcohol in the bloodstream.” The majority answers “It depends,” and so do I. The difference is that the majority offers no additional guidance, merely instructing courts and police officers to consider the totality of the circumstances. I believe more meaningful guidance can be provided about how to handle the typical cases, and nothing about the question presented prohibits affording that guidance.


Because the body’s natural metabolization of alcohol inevitably destroys evidence of the crime, it constitutes an exigent circumstance. As a result, I would hold that a warrantless blood draw does not violate the Fourth Amendment. . . .

The presence of “exigent circumstances” is [an] exception to the warrant requirement. Exigency applies when “ ‘the needs of law enforcement [are] so compelling that [a] warrantless search is objectively reasonable under the Fourth Amendment.’ ” Mincey v. Arizona (1978). Thus, when exigent circumstances are present, officers may take actions that would typically require a warrant, such as entering a home in hot pursuit of a fleeing suspect. As relevant in this case, officers may also conduct a warrantless search when they have probable cause to believe that failure to act would result in “imminent destruction of evidence.”

Once police arrest a suspect for drunk driving, each passing minute eliminates probative evidence of the crime. The human liver eliminates alcohol from the bloodstream at a rate of approximately 0.015 percent to 0.020 percent per hour with some heavy drinkers as high as 0.022 percent per hour, depending on, among other things, a person’s sex, weight, body type, and drinking history. The Court has acknowledged this fact since Schmerber v. California (1966), [where it] explained that drawing a person’s blood is “a highly effective means of determining the degree to which [he] is under the influence of alcohol” and is a reasonable procedure because blood tests are “commonplace” and “involv[e] virtually no risk, trauma, or pain.” The Court, therefore, held that dissipation of alcohol in the blood constitutes an exigency that allows a blood draw without a warrant.

The rapid destruction of evidence acknowledged by the parties, the majority, and Schmerber’s exigency determination occurs in every situation where police have probable cause to arrest a drunk driver. In turn, that destruction of evidence implicates the exigent-circumstances doctrine. . .

In today’s decision, the Court elides the certainty of evidence destruction in drunk-driving cases and focuses primarily on the time necessary for destruction. In doing so, it turns the exigency inquiry into a question about the amount of evidentiary destruction police must permit before they may act without a warrant. That inquiry is inconsistent with the actual exigency at issue: the uncontested destruction of evidence due to metabolization of alcohol. Moreover, the Court’s facts-and-circumstances analysis will be difficult to administer, a particularly important concern in the Fourth Amendment context. . . .

Further, the Court nowhere explains how an officer in the field is to apply the facts-and-circumstances test it adopts. First, officers do not have the facts needed to assess how much time can pass before too little evidence remains. They will never know how intoxicated a suspect is at the time of arrest. Otherwise, there would be no need for testing. Second, they will not know how long it will take to roust a magistrate from his bed, reach the hospital, or obtain a blood sample once there. . . .

The Court should not adopt a rule that requires police to guess whether they will be able to obtain a warrant before “too much” evidence is destroyed, for the police lack reliable information concerning the relevant variables. . . .

  For the foregoing reasons, I respectfully dissent.