Missouri v. McNeely

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LII note: The U.S. Supreme Court has now decided Missouri v. McNeely.

Court below: 

Tyler G. McNeely was arrested for drunk driving on October 3, 2010. After McNeely refused a breathalyzer and blood tests, Officer Mark Winder, acting without a warrant, directed hospital personnel to remove blood from McNeely. McNeely asserts that this action violated his Fourth Amendment right to be free from unreasonable searches and seizures. The State of Missouri responds that Winder’s action was constitutional because it fell into the “exigent circumstances” exception to the Fourth Amendment’s warrant requirement because the blood evidence was likely to be destroyed during the time it would take to obtain a warrant. McNeely also argues that bodily integrity is the core of the Fourth Amendment, that warrantless blood draws are unnecessary because other states have required warrants for blood draws and have not encountered difficulties enforcing DUI laws, and that judges and prosecutors overwhelmingly support warrants for blood draws. Missouri responds that blood testing is the best method of obtaining probative, relevant evidence of drunk driving, that blood draws typically involve little risk and pain, and that because alcohol naturally dissipates in a person’s bloodstream, evidence of drunk driving is continually destroyed.

Questions as Framed for the Court by the Parties 

Whether a law enforcement officer may obtain a nonconsensual and warrantless blood sample from a drunk driver under the exigent circumstances exception to the Fourth Amendment warrant requirement based upon the natural dissipation of alcohol in the bloodstream.


Is there an exception to the Fourth Amendment warrant requirement for forcibly drawing blood from a person suspected of drunk driving?



On October 3, 2010, at approximately 2:08 A.M., patrolman Mark Winder stopped Tyler G. McNeely for speeding. During the routine traffic stop, Winder thought McNeely showed signs of intoxication, including bloodshot eyes, slurred speech, and the smell of alcohol on his person. As a result, Winder had McNeely perform multiple field-sobriety tests. According to Winder’s later testimony, because McNeely performed poorly on each of these tests, Winder arrested McNeely for driving while intoxicated. Winder then asked McNeely to take a breathalyzer test, but McNeely refused.

Winder, relying on an article he had recently read in Traffic Safety News that was written by a prosecutor in the Missouri Attorney General’s Office, took McNeely to the local hospital for a blood test without first getting a search warrant. Upon arrival at the hospital, Winder read an implied consent advisory form to McNeely, in which he warned McNeely that he would lose his driver’s license for one year if he refused to consent to a blood test, and that such refusal would be admissible evidence in a future prosecution against McNeely. After McNeely refused the blood test, Winder then instructed a staff member to draw blood without McNeely’s permission. The result of the test was a blood-alcohol level of 0.154 percent, well above the legal limit of 0.08.

After the state charged McNeely with driving while intoxicated, McNeely filed a motion to suppress evidence due to a violation of his Fourth Amendment right to be free from unreasonable searches and seizures. The trial court sustained this motion. On June 21, 2011, the Missouri Court of Appeals, Eastern District, reversed the trial court, holding that the exigent circumstances exception to the Fourth Amendment applied so Winder did not need a warrant. Subsequently, in light of the “general interest and importance of the issue,” the Court of Appeals sua sponte transferred the case to the Missouri Supreme Court. The Missouri Supreme Court reversed the Court of Appeals and affirmed the trial’s ruling in a per curiam opinion. The U.S. Supreme Court granted certiorari on September 25, 2012, on the question of whether the natural dissipation of alcohol in the bloodstream triggers the exigent circumstances exception to the Fourth Amendment.



This case centers on the consequences of allowing warrantless and nonconsensual blood tests for suspicion of drunk driving. The State of Missouri and its Amici argue that the government needs to have the ability to perform nonconsensual blood tests to effectively enforce laws against drunk driving, and Fourth Amendment privacy interests are minimal for motorists. McNeely and Amici counter that there are significant privacy implications in a person’s body, that warrantless blood draws are unnecessary to enforce drunk driving laws, and that the warrant process can be streamlined, removing any exigent circumstances.

The Right Against Bodily Intrusion

The state of Missouri and Mothers Against Drunk Driving (“MADD”) both note the extent of drunk driving in the United States: in 2010, the nationwide death toll as a result of drunk drivers was 10,228. Missouri also considers drunk driving a serious crime, with a first offense authorizing a prison sentence of up to six months, and a fifth offense authorizing a sentence of up to fifteen years. Furthermore, MADD notes that the estimated annual cost of drunk-driving crashes is $132 billion, even before accounting for long-term health care and lost output costs. Missouri also argues that blood testing is the best method of getting probative, relevant evidence of drunk driving. The National District Attorney’s Association (“NDAA”) points out that blood tests are necessary for a variety of events in modern life, such as medical exams, marriage licenses, entry for some colleges, and joining the military. The United States adds that blood draws typically involve “virtually no risk, trauma, or pain.”

McNeely responds that bodily integrity is the heart of human dignity and privacy. McNeely compares drawing blood to practices such as taking fingernail scrapings and searching a person’s clothing for evidence, which have been held to “inflict great indignity and arouse strong resentment.” McNeely is also concerned about the environment of the blood draw, pointing out that some states authorize officers to draw blood at the location of the arrest, a circumstance he asserts is much more likely to cause pain or serious injury. The National College for DUI Defense (“NCDD”) and the National Association of Criminal Defense Lawyers (“NACDL”) argue that warrantless blood draws are unnecessary. They note that twenty-one states, including Missouri, have typically obtained warrants for blood draws involving alcohol tests, and they assert that these warrant requirements have not created difficulties in enforcing drug laws. In addition, the NCDD and NACDL cite a National Highway Traffic Safety Administration study, which found that judges and prosecutors overwhelmingly support warrants for blood draws because they constitute better evidence and lead to “more guilty pleas, fewer trials, and more convictions.”

The Destruction of Evidence

Missouri argues that because blood naturally dissipates in a person’s bloodstream, evidence of drunk driving is continually and inevitably destroyed. The NDAA asserts that the process for obtaining a warrant is time-consuming because the warrant-seeker must locate a judge and the judge must review the warrant request. Moreover, the time it takes to obtain a warrant can depend on multiple factors, including the day of the week and the time of the day. The NDAA also claims that increases in technology to streamline the process of obtaining a warrant will not be available in every jurisdiction and that such disparity is unviable.

The NCDD and NACDL assert that the process for obtaining a warrant and drawing blood typically takes less than two hours. They respond to the inevitable destruction of evidence argument by pointing out that the rate of dissipation is predictable and provides police a reasonable “window of opportunity” in which to obtain a warrant. McNeely notes that many states allow for methods of electronic warrant transmission, such as submitting affidavits by telephone, e-mail warrants, or text messaging, which expedites the process. McNeely cites a publication of the Kansas County and District Attorneys Association that concludes that technology can decrease the time to obtain a warrant from three hours to forty-five minutes.



Both parties start from the Supreme Court’s repeatedly stated maxim that the “ultimate touchstone of the Fourth Amendment is reasonableness.” Both parties agree that warrantless searches and seizures are presumptively unreasonable. Nevertheless, the Supreme Court has recognized that exigent circumstances may justify a warrantless search. Some examples of judicially recognized exigent circumstances include “hot pursuit” of a fleeing suspect, the need to fight a fire, and the need to render emergency assistance to an injured individual. Moreover, the Supreme Court recently confirmed that imminent destruction of evidence is an exigent circumstance that may justify a warrantless search. Ultimately, the analysis balances the expectations of individual privacy against the legitimacy of the government’s asserted interests.

The Reasonableness of Obtaining Warrantless Blood Tests from Suspected Drunk Drivers

Missouri argues that the facts in this case are a reasonable application of the “imminent destruction of evidence” exception to the Fourth Amendment’s warrant requirement. Specifically, Missouri emphasizes that the exception is particularly appropriate here because the human body always eliminates alcohol, whereas most other evidence is only subject to likely destruction or disappearance. Moreover, Missouri argues that this evidence is the “best and most probative” evidence in a drunk driving investigation.

Missouri also argues that significant precedent favors its position. First, Missouri notes that numerous state courts, including those in Wisconsin, Minnesota, and Oregon, have held that law enforcement may perform a warrantless blood test in these circumstances. These state courts have essentially recognized a “blood alcohol exception” as an extension of the Supreme Court’s holding in Cupp v. Murphy where the Court held that police justifiably removed – without a warrant – a substance that appeared to be dried blood from underneath a suspect’s fingernails. Similarly, Missouri distinguishes this case from Vale v. Louisiana, where the Supreme Court refused to find exigency when the police, acting without a warrant, searched a home for heroin after confirming that no individuals were inside the home. While the facts in Vale indicate essentially no probability of destruction of evidence, here, by contrast, the human body always eliminates blood alcohol evidence, so the exigency always exists. Missouri also states that a ruling for McNeely would effectively force police to allow this evidence to disappear and would be “wholly inconsistent with . . . the Fourth Amendment.”

Conversely, McNeely argues that the Supreme Court disfavors per se exceptions to the Fourth Amendment’s warrant requirement and that a per se rule in this case is unreasonable. To support this assertion, McNeely cites language from the Court’s recent decision in United States v. Banks, where the Court stated that “no template is likely to produce sounder results than examining the totality of the circumstances in a given case.” While acknowledging that exigent circumstances sometimes justify exceptions to the warrant requirement, McNeely argues that the Supreme Court requires a “totality-of-the-circumstances” balancing test.

McNeely argues that courts should consider how far the police must take the suspect to have his or her blood drawn, how long it typically takes to obtain a warrant in the relevant jurisdiction, and whether state evidentiary rules impose strict requirements on the time interval between arrest and testing for blood-alcohol content. Finally, McNeely questions Missouri’s reliance on precedent that Missouri cited. Indeed, McNeely notes that Cupp supported an exception to the warrant requirement because the suspect there was rubbing his hands together to remove the dried blood from underneath his fingernails.

Balancing the State’s Legitimate Interests Against the Individual’s Privacy Interests

Missouri asserts that a state’s interest in preventing drunk driving and enforcing laws is both legitimate and essential. Missouri notes that, in 2010 alone, drunk driving caused at least 10,228 deaths and approximately $132 billion in damage. Additionally, Missouri cites language from Winston v. Lee, where Justice William J. Brennan stressed that “especially given the difficulty of proving drunkenness by other means, . . . results of the blood test were of vital importance if the State were to enforce its drunken driving laws.”

Similarly, Missouri asserts that the state’s interest outweighs any countervailing, individual privacy concerns. First, Missouri argues that a blood test poses only a minor intrusion because the Supreme Court has described blood tests as both commonplace and presenting little risk of trauma or pain. Furthermore, Missouri cites the Supreme Court’s decision in New York v. Class for the proposition that automobile use is already heavily regulated by the government, so all drivers assume a lower expectation of privacy. Missouri argues that this reduced expectation of privacy is particularly important in state efforts to stop drunk driving which poses a serious threat to public safety.

McNeely discounts the importance of the governmental interest at stake in this case. First, McNeely responds that at least half of the states prohibit warrantless blood draws and that no evidence indicates that these states have a greater problem with drunk driving enforcement. As an additional matter, McNeely argues that the state’s need for blood withdrawals is insubstantial because more than 80% of suspected drunk drivers consent to breathalyzer tests. Finally, McNeely argues that studies which indicate that those who refuse blood-alcohol content testing face higher average sanctions further undermines the need for a per se exception.

Conversely, McNeely argues that the privacy interest at stake here is substantial because the right to bodily integrity lies at the heart of the Fourth Amendment. In support of this claim, McNeely cites the ancient legal treatise by William Blackstone who stated that individuals have an absolute right against intrusion of his life or body. Similarly, McNeely argues that Justice Sandra Day O’Connor’s language in Cruzan v. Director, Missouri Dept. of Health echoes Blackstone’s earlier arguments: “[T]he Court has often deemed state incursions into the body repugnant to the interests protected by . . . Fourth Amendment jurisprudence.” As a final matter, McNeely disagrees with Missouri’s interpretation of Class and highlights the Supreme Court’s distinction between cars and people in terms of the privacy expectation.



McNeely asserts that a warrantless blood test violated his Fourth Amendment right to be free from unreasonable searches and seizures, and that a contrary ruling poses a grave threat to bodily integrity. Furthermore, McNeely argues that the state’s need for warrantless blood tests is insubstantial because most drunk driving suspects consent either to breathalyzer or blood tests. Missouri responds that allowing warrantless blood draws in these cases allows the state to more effectively pursue a vital interest in enforcing drunk driving laws and that the blood test constitutes only a minor intrusion which involves virtually no health risks. Furthermore, Missouri asserts that warrantless blood tests may be necessary because the delay in obtaining a warrant may allow the drunk driving suspect to partly or wholly metabolize the alcohol and thus destroy the most probative evidence of drunk driving. While both parties agree that drunk driving is a serious problem, they disagree sharply over whether allowing warrantless blood draws will enable states to more effectively enforce drunk driving laws and prosecute individuals suspected of violating those laws.


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