NOTICE: This opinion is subject to formal revision before publication in the preliminary print of the United States Reports. Readers are requested to notify the Reporter of Decisions, Supreme Court of the United States, Washington, D. C. 20543, of any typographical or other formal errors, in order that corrections may be made before the preliminary print goes to press.
SUPREME COURT OF THE UNITED STATES
Nos. 14–1468, 14–1470, and 14–1507
DANNY BIRCHFIELD, PETITIONER
on writ of certiorari to the supreme court ofnorth dakota
WILLIAM ROBERT BERNARD, Jr., PETITIONER
on writ of certiorari to the supreme court ofminnesota
STEVE MICHAEL BEYLUND, PETITIONER
GRANT LEVI, DIRECTOR, NORTH DAKOTA DEPARTMENT OF TRANSPORTATION
on writ of certiorari to the supreme court ofnorth dakota
[June 23, 2016]
Justice Alito delivered the opinion of the Court.
Drunk drivers take a grisly toll on the Nation’s roads, claiming thousands of lives, injuring many more victims, and inflicting billions of dollars in property damage every year. To fight this problem, all States have laws that prohibit motorists from driving with a blood alcohol concentration (BAC) that exceeds a specified level. But determining whether a driver’s BAC is over the legal limit requires a test, and many drivers stopped on suspicion of drunk driving would not submit to testing if given the option. So every State also has long had what are termed “implied consent laws.” These laws impose penalties on motorists who refuse to undergo testing when there is sufficient reason to believe they are violating the State’s drunk-driving laws.
In the past, the typical penalty for noncompliance was suspension or revocation of the motorist’s license. The cases now before us involve laws that go beyond that and make it a crime for a motorist to refuse to be tested after being lawfully arrested for driving while impaired. The question presented is whether such laws violate the Fourth Amendment’s prohibition against unreasonable searches.
The problem of drunk driving arose almost as soon as motor vehicles came into use. See J. Jacobs, Drunk Driving: An American Dilemma 57 (1989) (Jacobs). New Jersey enacted what was perhaps the Nation’s first drunk-driving law in 1906, 1906 N. J. Laws pp. 186, 196, and other States soon followed. These early laws made it illegal to drive while intoxicated but did not provide a statistical definition of intoxication. As a result, prosecutors normally had to present testimony that the defendant was showing outward signs of intoxication, like imbalance or slurred speech. R. Donigan, Chemical Tests and the Law 2 (1966) (Donigan). As one early case put it, “[t]he effects resulting from the drinking of intoxicating liquors are manifested in various ways, and before any one can be shown to be under the influence of intoxicating liquor it is necessary for some witness to prove that some one or more of these effects were perceptible to him.” State
, 119 Ore. 674, 677, 250 P. 833, 834 (1926).
The 1930’s saw a continued rise in the number of motor vehicles on the roads, an end to Prohibition, and not coincidentally an increased interest in combating the growing problem of drunk driving. Jones, Measuring Alcohol in Blood and Breath for Forensic Purposes—A Historical Review, 8 For. Sci. Rev. 13, 20, 33 (1996) (Jones). The American Medical Association and the National Safety Council set up committees to study the problem and ultimately concluded that a driver with a BAC of 0.15% or higher could be presumed to be inebriated. Donigan 21–22. In 1939, Indiana enacted the first law that defined presumptive intoxication based on BAC levels, using the recommended 0.15% standard. 1939 Ind. Acts p. 309; Jones 21. Other States soon followed and then, in response to updated guidance from national organizations, lowered the presumption to a BAC level of 0.10%. Don-igan 22–23. Later, States moved away from mere presumptions that defendants might rebut, and adopted laws providing that driving with a 0.10% BAC or higher was per se
illegal. Jacobs 69–70.
Enforcement of laws of this type obviously requires the measurement of BAC. One way of doing this is to analyze a sample of a driver’s blood directly. A technician with medical training uses a syringe to draw a blood sample from the veins of the subject, who must remain still during the procedure, and then the sample is shipped to a separate laboratory for measurement of its alcohol concentration. See 2 R. Erwin, Defense of Drunk Driving Cases §§17.03–17.04 (3d ed. 2015) (Erwin). Although it is possible for a subject to be forcibly immobilized so that a sample may be drawn, many States prohibit drawing blood from a driver who resists since this practice helps “to avoid violent confrontations.” South Dakota
, 459 U. S. 553,559 (1983).
The most common and economical method of calculating BAC is by means of a machine that measures the amount of alcohol in a person’s breath. National Highway Traffic Safety Admin. (NHTSA), E. Haire, W. Leaf, D. Preusser, & M. Solomon, Use of Warrants to Reduce Breath Test Refusals: Experiences from North Carolina 1 (No. 811461, Apr. 2011). One such device, called the “Drunkometer,” was invented and first sold in the 1930’s. Note, 30 N. C. L. Rev. 302, 303, and n. 10 (1952). The test subject would inflate a small balloon, and then the test analyst would release this captured breath into the machine, which forced it through a chemical solution that reacted to the presence of alcohol by changing color. Id.,
The test analyst could observe the amount of breath required to produce the color change and calculate the subject’s breath alcohol concentration and by extension, BAC, from this figure. Id.,
at 303–304. A more practical machine, called the “Breathalyzer,” came into common use beginning in the 1950’s, relying on the same basic scientific principles. 3 Erwin §22.01, at 22–3; Jones 34.
Over time, improved breath test machines were developed. Today, such devices can detect the presence of alcohol more quickly and accurately than before, typically using infrared technology rather than a chemical reaction. 2 Erwin §18A.01; Jones 36. And in practice all breath testing machines used for evidentiary purposes must be approved by the National Highway Traffic Safety Administration. See 1 H. Cohen & J. Green, Apprehending and Prosecuting the Drunk Driver §7.04 (LexisNexis 2015). These machines are generally regarded as very reliable because the federal standards require that the devices produce accurate and reproducible test results at a variety of BAC levels, from the very low to the very high. 77 Fed. Reg. 35747 (2012); 2 Erwin §18.07; Jones 38; see also California
,467 U. S. 479,489 (1984).
Measurement of BAC based on a breath test requires the cooperation of the person being tested. The subject must take a deep breath and exhale through a mouthpiece that connects to the machine. Berger, How Does it Work? Alcohol Breath Testing, 325 British Medical J. 1403 (2002) (Berger). Typically the test subject must blow air into the device “ ‘for a period of several seconds’ ” to produce an adequate breath sample, and the process is sometimes repeated so that analysts can compare multiple samples to ensure the device’s accuracy. Trombetta
at 481; see also 2 Erwin §21.04[b](L), at 21–14 (describing the Intoxilyzer 4011 device as requiring a 12-second exhalation, although the subject may take a new breath about halfway through).
Modern breath test machines are designed to capture so-called “deep lung” or alveolar air. Trombetta
at 481. Air from the alveolar region of the lungs provides the best basis for determining the test subject’s BAC, for it is in that part of the lungs that alcohol vapor and other gases are exchanged between blood and breath. 2 Erwin §18.01[a], at 18–7.
When a standard infrared device is used, the whole process takes only a few minutes from start to finish. Berger 1403; 2 Erwin §18A.03, at 18A–14. Most evidentiary breath tests do not occur next to the vehicle, at the side of the road, but in a police station, where the controlled environment is especially conducive to reliable testing, or in some cases in the officer’s patrol vehicle or in special mobile testing facilities. NHTSA, A. Berning et al., Refusal of Intoxication Testing: A Report to Congress 4, and n. 5 (No. 811098, Sept. 2008).
Because the cooperation of the test subject is necessary when a breath test is administered and highly preferable when a blood sample is taken, the enactment of laws defining intoxication based on BAC made it necessary for States to find a way of securing such cooperation.[1
] So-called “implied consent” laws were enacted to achieve this result. They provided that cooperation with BAC testing was a condition of the privilege of driving on state roads and that the privilege would be rescinded if a suspected drunk driver refused to honor that condition. Donigan 177. The first such law was enacted by New York in 1953, and many other States followed suit not long thereafter. Id.,
at 177–179. In 1962, the Uniform Vehicle Code also included such a provision. Id.,
at 179. Today, “all 50 States have adopted implied consent laws that require motorists, as a condition of operating a motor vehicle within the State, to consent to BAC testing if they are arrested or otherwise detained on suspicion of a drunk-driving offense.” Missouri
, 569 U. S. ___, ___ (2013) (plurality opinion) (slip op., at 18). Suspension or revocation of the motorist’s driver’s license remains the standard legal consequence of refusal. In addition, evidence of the motorist’s refusal is admitted as evidence of likely intoxication in a drunk-driving prosecution. See ibid.
In recent decades, the States and the Federal Government have toughened drunk-driving laws, and those efforts have corresponded to a dramatic decrease in alcohol-related fatalities. As of the early 1980’s, the number of annual fatalities averaged 25,000; by 2014, the most recent year for which statistics are available, the number had fallen to below 10,000. Presidential Commission on Drunk Driving 1 (Nov. 1983); NHTSA, Traffic Safety Facts, 2014 Data, Alcohol-Impaired Driving 2 (No. 812231, Dec. 2015) (NHTSA, 2014 Alcohol-Impaired Driving). One legal change has been further lowering the BAC standard from 0.10% to 0.08%. See 1 Erwin, §2.01, at 2–3 to 2–4. In addition, many States now impose increased penalties for recidivists and for drivers with a BAC level that exceeds a higher threshold. In North Dakota, for example, the standard penalty for first-time drunk-driving offenders is license suspension and a fine. N. D. Cent. Code Ann. §39–08–01(5)(a)(1) (Supp. 2015); §39–20–04.1(1). But an offender with a BAC of 0.16% or higher must spend at least two days in jail. §39–08–01(5)(a)(2). In addition, the State imposes increased mandatory minimum sentences for drunk-driving recidivists. §§39–08–01(5)(b)–(d).
Many other States have taken a similar approach, but this new structure threatened to undermine the effectiveness of implied consent laws. If the penalty for driving with a greatly elevated BAC or for repeat violations exceeds the penalty for refusing to submit to testing, motorists who fear conviction for the more severely punished offenses have an incentive to reject testing. And in some States, the refusal rate is high. On average, over one-fifth of all drivers asked to submit to BAC testing in 2011 refused to do so. NHTSA, E. Namuswe, H. Coleman, & A. Berning, Breath Test Refusal Rates in the United States—2011 Update 1 (No. 811881, Mar. 2014). In North Dakota, the refusal rate for 2011 was a representative 21%. Id.,
at 2. Minnesota’s was below average, at 12%. Ibid.
To combat the problem of test refusal, some States have begun to enact laws making it a crime to refuse to undergo testing. Minnesota has taken this approach for decades. See 1989 Minn. Laws p. 1658; 1992 Minn. Laws p. 1947. And that may partly explain why its refusal rate now is below the national average. Minnesota’s rate is also half the 24% rate reported for 1988, the year before its first criminal refusal law took effect. See Ross, Simon, Cleary, Lewis, & Storkamp, Causes and Consequences of Implied Consent Refusal, 11 Alcohol, Drugs and Driving 57, 69 (1995). North Dakota adopted a similar law, in 2013, after a pair of drunk-driving accidents claimed the lives of an entire young family and another family’s 5- and 9-year-old boys.[2
] 2013 N. D. Laws pp. 1087–1088 (codified at §§39–08–01(1)–(3)). The Federal Government also encourages this approach as a means for overcoming the incentive that drunk drivers have to refuse a test. NHTSA, Refusal of Intoxication Testing, at 20.
Petitioner Danny Birchfield accidentally drove his car off a North Dakota highway on October 10, 2013. A state trooper arrived and watched as Birchfield unsuccessfully tried to drive back out of the ditch in which his car was stuck. The trooper approached, caught a strong whiff of alcohol, and saw that Birchfield’s eyes were bloodshot and watery. Birchfield spoke in slurred speech and struggled to stay steady on his feet. At the trooper’s request, Birchfield agreed to take several field sobriety tests and performed poorly on each. He had trouble reciting sections of the alphabet and counting backwards in compliance with the trooper’s directions.
Believing that Birchfield was intoxicated, the trooper informed him of his obligation under state law to agree to a BAC test. Birchfield consented to a roadside breath test. The device used for this sort of test often differs from the machines used for breath tests administered in a police station and is intended to provide a preliminary assessment of the driver’s BAC. See, e.g.,
Berger 1403. Because the reliability of these preliminary or screening breath tests varies, many jurisdictions do not permit their numerical results to be admitted in a drunk-driving trial as evidence of a driver’s BAC. See generally 3 Erwin §24.03. In North Dakota, results from this type of test are “used only for determining whether or not a further test shall be given.” N. D. Cent. Code Ann. §39–20–14(3). In Birchfield’s case, the screening test estimated that his BAC was 0.254%, more than three times the legal limit of 0.08%. See §39–08–01(1)(a).
The state trooper arrested Birchfield for driving while impaired, gave the usual Miranda
warnings, again advised him of his obligation under North Dakota law to undergo BAC testing, and informed him, as state law requires, see §39–20–01(3)(a), that refusing to take the test would expose him to criminal penalties. In addition to mandatory addiction treatment, sentences range from a mandatory fine of $500 (for first-time offenders) to fines of at least $2,000 and imprisonment of at least one year and one day (for serial offenders). §39–08–01(5). These criminal penalties apply to blood, breath, and urine test refusals alike. See §§39–08–01(2), 39–20–01, 39–20–14.
Although faced with the prospect of prosecution under this law, Birchfield refused to let his blood be drawn. Just three months before, Birchfield had received a citation for driving under the influence, and he ultimately pleaded guilty to that offense. State
, Crim. No. 30–2013–CR–00720 (Dist. Ct. Morton Cty., N. D., Jan. 27, 2014). This time he also pleaded guilty—to a misde-meanor violation of the refusal statute—but his plea wasa conditional one: while Birchfield admitted refusing the blood test, he argued that the Fourth Amendment prohibited criminalizing his refusal to submit to the test. The State District Court rejected this argument and imposed a sentence that accounted for his prior conviction. Cf. §39–08–01(5)(b). The sentence included 30 days in jail (20 of which were suspended and 10 of which had already been served), 1 year of unsupervised probation, $1,750 in fine and fees, and mandatory participation in a sobriety program and in a substance abuse evaluation. App. to Pet. for Cert. in No. 14–1468, p. 20a.
On appeal, the North Dakota Supreme Court affirmed. 2015 ND 6, 858 N. W. 2d 302. The court found support for the test refusal statute in this Court’s McNeely
plurality opinion, which had spoken favorably about “acceptable ‘legal tools’ with ‘significant consequences’ for refusing to submit to testing.” 858 N. W. 2d, at 307 (quoting McNeely
, 569 U. S., at ___ (slip op., at 18)).
On August 5, 2012, Minnesota police received a report of a problem at a South St. Paul boat launch. Three apparently intoxicated men had gotten their truck stuck in the river while attempting to pull their boat out of the water. When police arrived, witnesses informed them that a man in underwear had been driving the truck. That man proved to be William Robert Bernard, Jr., petitioner in the second of these cases. Bernard admitted that he had been drinking but denied driving the truck (though he was holding its keys) and refused to perform any field sobriety tests. After noting that Bernard’s breath smelled of alcohol and that his eyes were bloodshot and watery, officers arrested Bernard for driving while impaired.
Back at the police station, officers read Bernard Minnesota’s implied consent advisory, which like North Dakota’s informs motorists that it is a crime under state law to refuse to submit to a legally required BAC test. See Minn. Stat. §169A.51, subd. 2 (2014). Aside from noncriminal penalties like license revocation, §169A.52, subd. 3, test refusal in Minnesota can result in criminal penalties ranging from no more than 90 days’ imprisonment and up to a $1,000 fine for a misdemeanor violation to seven years’ imprisonment and a $14,000 fine for repeat offenders, §169A.03, subd. 12; §169A.20, subds. 2–3; §169A.24, subd. 2; §169A.27, subd. 2.
The officers asked Bernard to take a breath test. After he refused, prosecutors charged him with test refusal in the first degree because he had four prior impaired-driving convictions. 859 N. W. 2d 762, 765, n. 1 (Minn. 2015) (case below). First-degree refusal carries the highest maximum penalties and a mandatory minimum 3-year prison sentence. §169A.276, subd. 1.
The Minnesota District Court dismissed the charges on the ground that the warrantless breath test demanded of Bernard was not permitted under the Fourth Amendment. App. to Pet. for Cert. in No. 14–1470, pp. 48a, 59a. The Minnesota Court of Appeals reversed, id.,
at 46a, and the State Supreme Court affirmed that judgment. Based on the longstanding doctrine that authorizes warrantless searches incident to a lawful arrest, the high court concluded that police did not need a warrant to insist on a test of Bernard’s breath. 859 N. W. 2d, at 766–772. Two justices dissented. Id.,
at 774–780 (opinion of Page and Stras, JJ.).
A police officer spotted our third petitioner, Steve Michael Beylund, driving the streets of Bowman, North Dakota, on the night of August 10, 2013. The officer saw Beylund try unsuccessfully to turn into a driveway. In the process, Beylund’s car nearly hit a stop sign before coming to a stop still partly on the public road. The officer walked up to the car and saw that Beylund had an empty wine glass in the center console next to him. Noticing that Beylund also smelled of alcohol, the officer asked him to step out of the car. As Beylund did so, he struggled to keep his balance.
The officer arrested Beylund for driving while impaired and took him to a nearby hospital. There he read Beylund North Dakota’s implied consent advisory, informing him that test refusal in these circumstances is itself a crime. See N. D. Cent. Code Ann. §39–20–01(3)(a). Unlike the other two petitioners in these cases, Beylund agreed to have his blood drawn and analyzed. A nurse took a blood sample, which revealed a blood alcohol concentration of 0.250%, more than three times the legal limit.
Given the test results, Beylund’s driver’s license was suspended for two years after an administrative hearing. Beylund appealed the hearing officer’s decision to a North Dakota District Court, principally arguing that his consent to the blood test was coerced by the officer’s warning that refusing to consent would itself be a crime. The District Court rejected this argument, and Beylund again appealed.
The North Dakota Supreme Court affirmed. In response to Beylund’s argument that his consent was insufficiently voluntary because of the announced criminal penalties for refusal, the court relied on the fact that its then-recent Birchfield
decision had upheld the constitutionality of those penalties. 2015 ND 18, ¶¶14–15, 859 N. W. 2d 403, 408–409. The court also explained that it had found consent offered by a similarly situated motorist to be voluntary, State
, 2014 ND 152, 849 N. W. 2d 599. In that case, the court emphasized that North Dakota’s implied consent advisory was not misleading because it truthfully related the penalties for refusal. Id.,
We granted certiorari in all three cases and consolidated them for argument, see 577 U. S. ___ (2015), in order to decide whether motorists lawfully arrested for drunk driving may be convicted of a crime or otherwise penalized for refusing to take a warrantless test measuring the alcohol in their bloodstream.
As our summary of the facts and proceedings in these three cases reveals, the cases differ in some respects. Petitioners Birchfield and Beylund were told that they were obligated to submit to a blood test, whereas petitioner Bernard was informed that a breath test was required. Birchfield and Bernard each refused to undergo a test and was convicted of a crime for his refusal. Beylund complied with the demand for a blood sample, and his license was then suspended in an administrative proceeding based on test results that revealed a very high blood alcohol level.
Despite these differences, success for all three petitioners depends on the proposition that the criminal law ordinarily may not compel a motorist to submit to the taking of a blood sample or to a breath test unless a warrant authorizing such testing is issued by a magistrate. If, on the other hand, such warrantless searches comport with the Fourth Amendment, it follows that a State may criminalize the refusal to comply with a demand to submit to the required testing, just as a State may make it a crime for a person to obstruct the execution of a valid search warrant. See, e.g.,
Conn. Gen. Stat. §54–33d (2009); Fla. Stat. §933.15 (2015); N. J. Stat. Ann. §33:1–63 (West 1994);18 U. S. C. §1501; cf. Bumper
v. North Carolina
,391 U. S. 543,550 (1968) (“When a law enforcement officer claims authority to search a home under a warrant, he announces in effect that the occupant has no right to resist the search”). And by the same token, if such warrantless searches are constitutional, there is no obstacle under federal law to the admission of the results that they yield in either a criminal prosecution or a civil or administrative proceeding. We therefore begin by considering whether the searches demanded in these cases were consistent with the Fourth Amendment.
The Fourth Amendment provides:
“The 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, supported by Oath or affirmation, and particularly describing the place to be searched, and the persons or things to be seized.”
The Amendment thus prohibits “unreasonable searches,” and our cases establish that the taking of a blood sam-ple or the administration of a breath test is a search.See Skinner
v. Railway Labor Executives’ Assn.
,489 U. S. 602–617 (1989); Schmerber
,384 U. S. 757–768 (1966). The question, then, is whether the warrantless searches at issue here were reasonable. See Vernonia School Dist. 47J
,515 U. S. 646,652 (1995) (“As the text of the Fourth Amendment indicates, the ultimate measure of the constitutionality of a governmental search is ‘reasonableness’ ”).
“[T]he text of the Fourth Amendment does not specify when a search warrant must be obtained.” Kentucky
,563 U. S. 452,459 (2011); see also California
,500 U. S. 565,581 (1991) (Scalia, J., concur-ring in judgment) (“What [the text] explicitly states regard-ing warrants is by way of limitation upon their issuance rather than requirement of their use”). But “this Court has inferred that a warrant must [usually] be secured.” King
, 563 U. S., at 459. This usual requirement, however, is subject to a number of exceptions. Ibid.
We have previously had occasion to examine whether one such exception—for “exigent circumstances”—applies in drunk-driving investigations. The exigent circum-stances exception allows a warrantless search when an emergency leaves police insufficient time to seek a warrant. Michigan
,436 U. S. 499,509 (1978). It permits, for instance, the warrantless entry of private property when there is a need to provide urgent aid to those inside, when police are in hot pursuit of a fleeing suspect, and when police fear the imminent destruction of evidence. King
, we held that drunk driving may
present such an exigency. There, an officer directed hospital personnel to take a blood sample from a driver who was receiving treatment for car crash injuries. 384 U. S., at 758. The Court concluded that the officer “might reasonably have believed that he was confronted with an emergency” that left no time to seek a warrant because “the percentage of alcohol in the blood begins to diminish shortly after drinking stops.” Id.,
at 770. On the specific facts of that case, where time had already been lost taking the driver to the hospital and investigating the accident, the Court found no Fourth Amendment violation even though the warrantless blood draw took place over the driver’s objection. Id.,
More recently, though, we have held that the natural dissipation of alcohol from the bloodstream does not always
constitute an exigency justifying the warrantless taking of a blood sample. That was the holding of Missouri
, 569 U. S. ___, where the State of Missouri was seeking a per se
rule 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 evidence is inherently evanescent.” Id.,
at ___ (opinion of the Court) (slip op., at 8). We disagreed, emphasizing that Schmerber
had adopted a case-specific analysis depending on “all of the facts and circumstances of the particular case.” 569 U. S., at ___ (slip op., at 8). We refused to “depart from careful case-by-case assessment of exigency and adopt the categorical rule proposed by the State.” Id.,
at ___ (slip op., at 9).
While emphasizing that the exigent-circumstances exception must be applied on a case-by-case basis, the McNeely
noted that other exceptions to the warrant requirement “apply categorically” rather than in a “case-specific” fashion. Id.,
at ___, n. 3 (slip op., at 7, n. 3). One of these, as the McNeely
opinion recognized, is the long-established rule that a warrantless search may be conducted incident to a lawful arrest. See ibid
. But the Court pointedly did not address any potential justification for warrantless testing of drunk-driving suspects except for the exception “at issue in th[e] case,” namely, the exception for exigent circumstances. Id.,
at ___ (slip op., at 5). Neither did any of the Justices who wrote separately. See id.,
at ___–___ (Kennedy, J., concurring in part)(slip op., at 1–2); id.,
at ___–___ (Roberts, C. J., concurring in part and dissenting in part) (slip op., at 1–11); id.,
at ___–___ (Thomas, J., dissenting) (slip op., at 1–8).
In the three cases now before us, the drivers were searched or told that they were required to submit to a search after being placed under arrest for drunk driving. We therefore consider how the search-incident-to-arrest doctrine applies to breath and blood tests incident to such arrests.
The search-incident-to-arrest doctrine has an ancient pedigree. Well before the Nation’s founding, it was recognized that officers carrying out a lawful arrest had the authority to make a warrantless search of the arrestee’s person. An 18th-century manual for justices of the peace provides a representative picture of usual practice shortly before the Fourth Amendment’s adoption:
“[A] thorough search of the felon is of the utmost consequence to your own safety, and the benefit of the public, as by this means he will be deprived of instruments of mischief, and evidence may probably be found on him sufficient to convict him, of which, if he has either time or opportunity allowed him, he will besure [sic] to find some means to get rid of.” The Conductor Generalis 117 (J. Parker ed. 1788) (reprinting S. Welch, Observations on the Office of Constable 19 (1754)).
One Fourth Amendment historian has observed that, prior to American independence, “[a]nyone arrested could expect that not only his surface clothing but his body, luggage, and saddlebags would be searched and, perhaps, his shoes, socks, and mouth as well.” W. Cuddihy, The Fourth Amendment: Origins and Original Meaning: 602–1791, p. 420 (2009).
No historical evidence suggests that the Fourth Amendment altered the permissible bounds of arrestee searches. On the contrary, legal scholars agree that “the legitimacy of body searches as an adjunct to the arrest process had been thoroughly established in colonial times, so much so that their constitutionality in 1789 can not be doubted.” Id.,
at 752; see also T. Taylor, Two Studies in Constitutional Interpretation 28–29, 39, 45 (1969); Stuntz, The Substantive Origins of Criminal Procedure, 105 Yale L. J. 393, 401 (1995).
Few reported cases addressed the legality of such searches before the 19th century, apparently because the point was not much contested. In the 19th century, the subject came up for discussion more often, but court decisions and treatises alike confirmed the searches’ broad acceptance. E.g., Holker
, 141 Mo. 527, 539–540, 42 S. W. 1090, 1093 (1897); Ex parte Hurn
, 92 Ala. 102, 112, 9 So. 515, 519 (1891); Thatcher
, 79 Me. 547, 548–549, 11 A. 599 (1887); Reifsnyder
, 44 Iowa 101, 103 (1876); F. Wharton, Criminal Pleading and Practice §60, p. 45 (8th ed. 1880); 1 J. Bishop, Criminal Procedure §211, p. 127 (2d ed. 1872).
When this Court first addressed the question, we too confirmed (albeit in dicta) “the right on the part of the Government, always recognized under English and American law, to search the person of the accused when legally arrested to discover and seize the fruits or evidence of crime.” Weeks
v. United States
,232 U. S. 383,392 (1914). The exception quickly became a fixture in our Fourth Amendment case law. But in the decades that followed, we grappled repeatedly with the question of the authority of arresting officers to search the area surrounding the arrestee, and our decisions reached results that were not easy to reconcile. See, e.g., United States
,285 U. S. 452,464 (1932) (forbidding “unrestrained” search of room where arrest was made); Harris
v. United States
,331 U. S. 145,149,152 (1947) (permitting complete search of arrestee’s four-room apartment); United States
,339 U. S. 56–65 (1950) (permitting complete search of arrestee’s office).
We attempted to clarify the law regarding searches incident to arrest in Chimel
,395 U. S. 752,754 (1969), a case in which officers had searched the arrestee’s entire three-bedroom house. Chimel
endorsed a general rule that arresting officers, in order to prevent the arrestee from obtaining a weapon or destroying evidence, could search both “the person arrested” and “the area ‘within his immediate control.’ ” Id.,
at 763. “[N]o comparable justification,” we said, supported “routinely searching any room other than that in which an arrest occurs—or, for that matter, for searching through all the desk drawers or other closed or concealed areas in that room itself.” Ibid.
Four years later, in United States
,414 U. S. 218 (1973), we elaborated on Chimel
’s meaning. We noted that the search-incident-to-arrest rule actually comprises “two distinct propositions”: “The first is that a search may be made of the person
of the arrestee by virtue of the lawful arrest. The second is that a search may be made of the area within the control of the arrestee.” 414 U. S., at 224. After a thorough review of the relevant common law history, we repudiated “case-by-case adjudication” of the question whether an arresting officer had the authority to carry out a search of the arrestee’s person. Id.,
at 235. The permissibility of such searches, we held, does not depend on whether a search of a particular
arrestee is likely to protect officer safety or evidence: “The authority to search the person incident to a lawful custodial arrest, while based upon the need to disarm and to discover evidence, does not depend on what a court may later decide was the probability in a particular arrest situation that weapons or evidence would in fact be found upon the person of the suspect.” Ibid.
Instead, the mere “fact of the lawful arrest” justifies “a full search of the person.” Ibid.
itself, that meant that police had acted permissibly in searching inside a package of cigarettes found on the man they arrested. Id.,
Our decision two Terms ago in Riley
, 573 U. S. ___ (2014), reaffirmed “Robinson
’s categorical rule” and explained how the rule should be applied in situations that could not have been envisioned when the Fourth Amendment was adopted. Id.,
at ___ (slip op., at 9). Riley
concerned a search of data contained in the memory of a modern cell phone. “Absent more precise guidance from the founding era,” the Court wrote, “we generally determine whether to exempt a given type of search from the warrant requirement ‘by assessing, on the one hand, the degree to which it intrudes upon an individual’s privacy and, on the other, the degree to which it is needed for the promotion of legitimate governmental interests.’ ” Ibid.
Blood and breath tests to measure blood alcohol concentration are not as new as searches of cell phones, but here, as in Riley
, the founding era does not provide any definitive guidance as to whether they should be allowed incident to arrest.[3
] Lacking such guidance, we engage in the same mode of analysis as in Riley
: we examine “the degree to which [they] intrud[e] upon an individual’s privacy and . . . the degree to which [they are] needed for the promotion of legitimate governmental interests.’ ” Ibid.
We begin by considering the impact of breath and blood tests on individual privacy interests, and we will discuss each type of test in turn.
Years ago we said that breath tests do not “implicat[e] significant privacy concerns.” Skinner
, 489 U. S., at 626. That remains so today.
First, the physical intrusion is almost negligible. Breath tests “do not require piercing the skin” and entail “a minimum of inconvenience.” Id.,
at 625. As Minnesota describes its version of the breath test, the process requires the arrestee to blow continuously for 4 to 15 seconds into a straw-like mouthpiece that is connected by a tube to the test machine. Brief for Respondent in No. 14–1470, p. 20. Independent sources describe other breath test devices in essentially the same terms. See supra,
at 5. The effort is no more demanding than blowing up a party balloon.
Petitioner Bernard argues, however, that the process is nevertheless a significant intrusion because the arrestee must insert the mouthpiece of the machine into his or her mouth. Reply Brief in No. 14–1470, p. 9. But there is nothing painful or strange about this requirement. The use of a straw to drink beverages is a common practice and one to which few object.
Nor, contrary to Bernard, is the test a significant intrusion because it “does not capture an ordinary exhalation of the kind that routinely is exposed to the public” but instead “ ‘requires a sample of “alveolar” (deep lung) air.’ ” Brief for Petitioner in No. 14–1470, p. 24. Humans have never been known to assert a possessory interest in or any emotional attachment to any
of the air in their lungs. The air that humans exhale is not part of their bodies. Exhalation is a natural process—indeed, one that is necessary for life. Humans cannot hold their breath for more than a few minutes, and all the air that is breathed into a breath analyzing machine, including deep lung air, sooner or later would be exhaled even without the test. See gener-ally J. Hall, Guyton and Hall Textbook of Medical Physiology 519–520 (13th ed. 2016).
In prior cases, we have upheld warrantless searches involving physical intrusions that were at least as significant as that entailed in the administration of a breath test. Just recently we described the process of collecting a DNA sample by rubbing a swab on the inside of a person’s cheek as a “negligible” intrusion. Maryland
, 569 U. S. ___, ___ (2013) (slip op., at 8). We have also upheld scraping underneath a suspect’s fingernails to find evidence of a crime, calling that a “very limited intrusion.” Cupp
,412 U. S. 291,296 (1973). A breath test is no more intrusive than either of these procedures.
Second, breath tests are capable of revealing only one bit of information, the amount of alcohol in the subject’s breath. In this respect, they contrast sharply with the sample of cells collected by the swab in Maryland
. Although the DNA obtained under the law at issue in that case could lawfully be used only for identification pur-poses, 569 U. S., at ___ (slip op., at 5), the process put into the possession of law enforcement authorities a sample from which a wealth of additional, highly personal information could potentially be obtained. A breath test, by contrast, results in a BAC reading on a machine, nothing more. No sample of anything is left in the possession of the police.
Finally, participation in a breath test is not an experience that is likely to cause any great enhancement in the embarrassment that is inherent in any arrest. See Skinner
, at 625 (breath test involves “a minimum of . . . embarrassment”). The act of blowing into a straw is not inherently embarrassing, nor are evidentiary breath tests administered in a manner that causes embarrassment. Again, such tests are normally administered in private at a police station, in a patrol car, or in a mobile testing facility, out of public view. See supra,
at 5. Moreover, once placed under arrest, the individual’s expectation of privacy is necessarily diminished. Maryland
at ___–___ (slip op., at 24–25).
For all these reasons, we reiterate what we said in Skinner
: A breath test does not “implicat[e] significant privacy concerns.” 489 U. S., at 626.
Blood tests are a different matter. They “require piercing the skin” and extract a part of the subject’s body. Skinner
at 625; see also McNeely
, 569 U. S., at ___ (opinion of the Court) (slip op., at 4) (blood draws are “a compelled physical intrusion beneath [the defendant’s] skin and into his veins”); id.,
at ___ (opinion of Roberts, C. J.) (slip op., at 9) (blood draws are “significant bodily intrusions”).
And while humans exhale air from their lungs many times per minute, humans do not continually shed blood. It is true, of course, that people voluntarily submit to the taking of blood samples as part of a physical examination, and the process involves little pain or risk. See id.,
at ___ (plurality opinion) (slip op., at 16) (citing Schmerber
, 384 U. S., at 771). Nevertheless, for many, the process is not one they relish. It is significantly more intrusive than blowing into a tube. Perhaps that is why many States’ implied consent laws, including Minnesota’s, specifically prescribe that breath tests be administered in the usual drunk-driving case instead of blood tests or give motorists a measure of choice over which test to take. See 1 Erwin §4.06; Minn. Stat. §169A.51, subd. 3.
In addition, a blood test, unlike a breath test, places in the hands of law enforcement authorities a sample that can be preserved and from which it is possible to extract information beyond a simple BAC reading. Even if the law enforcement agency is precluded from testing the blood for any purpose other than to measure BAC, the potential remains and may result in anxiety for the person tested.
Having assessed the impact of breath and blood testing on privacy interests, we now look to the States’ asserted need to obtain BAC readings for persons arrested for drunk driving.
The States and the Federal Government have a “paramount interest . . . in preserving the safety of . . . public highways.” Mackey
,443 U. S. 1,17 (1979). Although the number of deaths and injuries caused by motor vehicle accidents has declined over the years, the statistics are still staggering. See, e.g.,
NHTSA, Traffic Safety Facts 1995—Overview 2 (No. 95F7, 1995) (47,087 fatalities, 3,416,000 injuries in 1988); NHTSA, Traffic Safety Facts, 2014 Data, Summary of Motor Vehicle Crashes 1 (No. 812263, May 2016) (Table 1) (29,989 fatalities, 1,648,000 injuries in 2014).
Alcohol consumption is a leading cause of traffic fatalities and injuries. During the past decade, annual fatalities in drunk-driving accidents ranged from 13,582 deaths in 2005 to 9,865 deaths in 2011. NHTSA, 2014 Alcohol-Impaired Driving 2. The most recent data report a total of 9,967 such fatalities in 2014—on average, one death every 53 minutes. Id.,
at 1. Our cases have long recognized the “carnage” and “slaughter” caused by drunk drivers. Neville
, 459 U. S., at 558; Breithaupt
,352 U. S. 432,439 (1957).
Justice Sotomayor’s partial dissent suggests that States’ interests in fighting drunk driving are satisfied once suspected drunk drivers are arrested, since such arrests take intoxicated drivers off the roads where they might do harm. See post,
at 9 (opinion concurring in part and dissenting in part). But of course States are not solely concerned with neutralizing the threat posed by a drunk driver who has already gotten behind the wheel. They also have a compelling interest in creating effective “deterrent[s] to drunken driving” so such individuals make responsible decisions and do not become a threat to others in the first place. Mackey
To deter potential drunk drivers and thereby reduce alcohol-related injuries, the States and the Federal Government have taken the series of steps that we recounted earlier. See supra,
at 2–8. We briefly recapitulate. After pegging inebriation to a specific level of blood alcohol, States passed implied consent laws to induce motorists to submit to BAC testing. While these laws originally provided that refusal to submit could result in the loss of the privilege of driving and the use of evidence of refusal in a drunk-driving prosecution, more recently States and the Federal Government have concluded that these consequences are insufficient. In particular, license suspension alone is unlikely to persuade the most dangerous offenders, such as those who drive with a BAC significantly above the current limit of 0.08% and recidivists, to agree to a test that would lead to severe criminal sanctions. NHTSA, Implied Consent Refusal Impact, pp. xvii, 83 (No. 807765, Sept. 1991); NHTSA, Use of Warrants for Breath Test Refusal 1 (No. 810852, Oct. 2007). The laws at issue in the present cases—which make it a crime to refuse to submit to a BAC test—are designed to provide an incentive to cooperate in such cases, and we conclude that they serve a very important function.
Petitioners and Justice Sotomayor contend that the States and the Federal Government could combat drunk driving in other ways that do not have the same impact on personal privacy. Their arguments are unconvincing.
The chief argument on this score is that an officer making an arrest for drunk driving should not be allowed to administer a BAC test unless the officer procures a search warrant or could not do so in time to obtain usable test results. The governmental interest in warrantless breath testing, Justice Sotomayor claims, turns on “ ‘whether the burden of obtaining a warrant is likely to frustrate the governmental purpose behind the search.’ ” Post,
at 3–4 (quoting Camara
v. Municipal Court of City and County of San Francisco
,387 U. S. 523,533 (1967)).
This argument contravenes our decisions holding that the legality of a search incident to arrest must be judged on the basis of categorical rules. In Robinson
, for example, no one claimed that the object of the search, a package of cigarettes, presented any danger to the arresting officer or was at risk of being destroyed in the time that it would have taken to secure a search warrant. The Court nevertheless upheld the constitutionality of a warrantless search of the package, concluding that a categorical rule was needed to give police adequate guidance: “A police officer’s determination as to how and where to search the person of a suspect whom he has arrested is necessarily a quick ad hoc
judgment which the Fourth Amendment does not require to be broken down in each instance into an analysis of each step in the search.” 414 U. S., at 235; cf. Riley
, 573 U. S., at ___ (slip op., at 22) (“If police are to have workable rules, the balancing of the competing interests must in large part be done on a categorical basis—not in an ad hoc, case-by-case fashion by individual police officers” (brackets, ellipsis, and internal quotation marks omitted)).
It is not surprising, then, that the language Justice Sotomayor quotes to justify her approach comes not from our search-incident-to-arrest case law, but a case that addressed routine home searches for possible housing code violations. See Camara
, 387 U. S., at 526. Camara
’s express concern in the passage that the dissent quotes was “whether the public interest demands creation
of a general exception to the Fourth Amendment’s warrant requirement.” Id.,
at 533 (emphasis added). Camara
explain how to apply an existing exception, let alone the long-established exception for searches incident to a lawful arrest, whose applicability, as Robinson
make plain, has never turned on case-specific variables such as how quickly the officer will be able to obtain a warrant in the particular circumstances he faces.
In advocating the case-by-case approach, petitioners and Justice Sotomayor cite language in our McNeely
opinion. See Brief for Petitioner in No. 14–1468, p. 14; post,
at 12. But McNeely
concerned an exception to the warrant requirement—for exigent circumstances—that always requires case-by-case determinations. That was the basis for our decision in that case. 569 U. S., at ___ (slip op.,at 9). Although Justice Sotomayor contends that the categorical search-incident-to-arrest doctrine and case-by-case exigent circumstances doctrine are actually parts of a single framework, post,
at 6–7, and n. 3, in McNeely
the Court was careful to note that the decision did not address any other exceptions to the warrant requirement, 569 U. S., at ___, n. 3 (slip op., at 7, n. 3).
Petitioners and Justice Sotomayor next suggest that requiring a warrant for BAC testing in every case in which a motorist is arrested for drunk driving would not impose any great burden on the police or the courts. But of course the same argument could be made about searching through objects found on the arrestee’s possession, which our cases permit even in the absence of a warrant. What about the cigarette package in Robinson
? What if a motorist arrested for drunk driving has a flask in his pocket? What if a motorist arrested for driving while under the influence of marijuana has what appears to be a mari-juana cigarette on his person? What about an unmarked bottle of pills?
If a search warrant were required for every search incident to arrest that does not involve exigent circumstances, the courts would be swamped. And even if we arbitrarily singled out BAC tests incident to arrest for this special treatment, as it appears the dissent would do, see post,
at 12–14, the impact on the courts would be considerable. The number of arrests every year for driving under the influence is enormous—more than 1.1 million in 2014. FBI, Uniform Crime Report, Crime in the United States, 2014, Arrests 2 (Fall 2015). Particularly in sparsely populated areas, it would be no small task for courts to field a large new influx of warrant applications that could come on any day of the year and at any hour. In many jurisdictions, judicial officers have the authority to issue warrants only within their own districts, see, e.g.,
Fed. Rule Crim. Proc. 41(b); N. D. Rule Crim. Proc. 41(a) (2016–2017), and in rural areas, some districts may have only a small number of judicial officers.
North Dakota, for instance, has only 51 state district judges spread across eight judicial districts.[4
] Those judges are assisted by 31 magistrates, and there are no magistrates in 20 of the State’s 53 counties.[5
] At any given location in the State, then, relatively few state officials have authority to issue search warrants.[6
] Yet the State, with a population of roughly 740,000, sees nearly 7,000 drunk-driving arrests each year. Office of North Dakota Attorney General, Crime in North Dakota, 2014, pp. 5, 47 (2015). With a small number of judicial officers authorized to issue warrants in some parts of the State, the burden of fielding BAC warrant applications 24 hours per day, 365 days of the year would not be the light burden that petitioners and Justice Sotomayor suggest.
In light of this burden and our prior search-incident-to-arrest precedents, petitioners would at a minimum have to show some special need for warrants for BAC testing. It is therefore appropriate to consider the benefits that such applications would provide. Search warrants protect privacy in two main ways. First, they ensure that a search is not carried out unless a neutral magistrate makes an independent determination that there is probable cause to believe that evidence will be found. See, e.g., Riley
, 573 U. S., at ___ (slip op., at 5). Second, if the magistrate finds probable cause, the warrant limits the intrusion on privacy by specifying the scope of the search—that is, the area that can be searched and the items that can be sought. United States
,433 U. S. 1,9 (1977), abrogated on other grounds, Acevedo
,500 U. S. 565.
How well would these functions be performed by the warrant applications that petitioners propose? In order to persuade a magistrate that there is probable cause for a search warrant, the officer would typically recite the same facts that led the officer to find that there was probable cause for arrest, namely, that there is probable cause to believe that a BAC test will reveal that the motorist’s blood alcohol level is over the limit. As these three cases suggest, see Part II, supra,
the facts that establish probable cause are largely the same from one drunk-driving stop to the next and consist largely of the officer’s own characterization of his or her observations—for example, that there was a strong odor of alcohol, that the motorist wobbled when attempting to stand, that the motorist paused when reciting the alphabet or counting backwards, and so on. A magistrate would be in a poor position to challenge such characterizations.
As for the second function served by search warrants—delineating the scope of a search—the warrants in question here would not serve that function at all. In every case the scope of the warrant would simply be a BAC test of the arrestee. Cf. Skinner
, 489 U. S., at 622 (“[I]n light of the standardized nature of the tests and the minimal discretion vested in those charged with administering the program, there are virtually no facts for a neutral magistrate to evaluate”).
For these reasons, requiring the police to obtain a warrant in every case would impose a substantial burden but no commensurate benefit.
Petitioners advance other alternatives to warrantless BAC tests incident to arrest, but these are poor substitutes. Relying on a recent NHTSA report, petitioner Birchfield identifies 19 strategies that he claims would be at least as effective as implied consent laws, including high-visibility sobriety checkpoints, installing ignition interlocks on repeat offenders’ cars that would disable their operation when the driver’s breath reveals a sufficiently high alcohol concentration, and alcohol treatment programs. Brief for Petitioner in No. 14–1468, at 44–45. But Birchfield ignores the fact that the cited report describes many of these measures, such as checkpoints, as significantly more costly than test refusal penalties. NHTSA, A. Goodwin et al., Countermeasures That Work: A Highway Safety Countermeasures Guide for State Highway Safety Offices, p. 1–7 (No. 811727, 7th ed. 2013). Others, such as ignition interlocks, target only a segment of the drunk-driver population. And still others, such as treatment programs, are already in widespread use, see id.,
at 1–8, including in North Dakota and Minnesota. Moreover, the same NHTSA report, in line with the agency’s guidance elsewhere, stresses that BAC test refusal penalties would be more
effective if the consequences for refusal were made more severe, including through the addition of criminal penalties. Id.,
at 1–16 to 1–17.
Petitioner Bernard objects to the whole idea of analyzing breath and blood tests as searches incident to arrest. That doctrine, he argues, does not protect the sort of governmental interests that warrantless breath and blood tests serve. On his reading, this Court’s precedents
permit a search of an arrestee solely to prevent the arrestee from obtaining a weapon or taking steps to destroy evidence. See Reply Brief in No. 14–1470, at 4–6. In Chimel
, for example, the Court derived its limitation for the scope of the permitted search—“the area into which an arrestee might reach”—from the principle that officers may reasonably search “the area from within which he might gain possession of a weapon or destructible evidence.” 395 U. S., at 763.
Stopping an arrestee from destroying evidence, Bernard argues, is critically different from preventing the loss of blood alcohol evidence as the result of the body’s metabolism of alcohol, a natural process over which the arrestee has little control. Reply Brief in No. 14–1470, at 5–6.
The distinction that Bernard draws between an arrestee’s active destruction of evidence and the loss of evidence due to a natural process makes little sense. In both situations the State is justifiably concerned that evidence may be lost, and Bernard does not explain why the cause of the loss should be dispositive. And in fact many of this Court’s post-Chimel
cases have recognized the State’s concern, not just in avoiding an arrestee’s intentional destruction of evidence, but in “evidence preservation” or avoiding “the loss of evidence” more generally. Riley
, 573 U. S., at ___ (slip op., at 8); see also Robinson
, 414 U. S., at 234 (“the need to preserve evidence on his person”); Knowles
,525 U. S. 113–119 (1998) (“the need to discover and preserve evidence;” “the concern for destruction or loss
of evidence” (emphasis added)); Virginia
,553 U. S. 164,176 (2008) (the need to “safeguard evidence”). This concern for preserving evidence or preventing its loss readily encompasses the inevitable metabolization of alcohol in the blood.
Nor is there any reason to suspect that Chimel
’s use of the word “destruction,” 395 U. S., at 763, was a deliberate decision to rule out evidence loss that is mostly beyond the arrestee’s control. The case did not involve any evidence that was subject to dissipation through natural processes, and there is no sign in the opinion that such a situation was on the Court’s mind.
Bernard attempts to derive more concrete support for his position from Schmerber
In that case, the Court stated that the “destruction of evidence under the direct control of the accused” is a danger that is not present “with respect to searches involving intrusions beyond the body’s surface.” 384 U. S., at 769. Bernard reads this to mean that an arrestee cannot be required “to take a chemical test” incident to arrest, Brief for Petitioner in No. 14–1470, at 19, but by using the term “chemical test,” Bernard obscures the fact that Schmerber
’s passage was addressed to the type of test at issue in that case, namely a blood test. The Court described blood tests as “searches involving intrusions beyond the body’s surface,” and it saw these searches as implicating important “interests in human dignity and privacy,” 384 U. S., at 769–770. Al-though the Court appreciated as well that blood tests “in-volv[e] virtually no risk, trauma, or pain,” id.,
at 771, its point was that such searches still impinge on far more sensitive interests than the typical search of the person of an arrestee. Cf. supra,
at 22–23. But breath tests, unlike blood tests, “are not
invasive of the body,” Skinner
, 489 U. S., at 626 (emphasis added), and therefore the Court’s comments in Schmerber
are inapposite when it comes to the type of test Bernard was asked to take. Schmerber
did not involve a breath test, and on the question of breath tests’ legality, Schmerber
Finally, Bernard supports his distinction using a passage from the McNeely
opinion, which distinguishes between “easily disposable evidence” over “which the suspect has control” and evidence, like blood alcohol evidence, that is lost through a natural process “in a gradual and relatively predictable manner.” 569 U. S., at ___ (slip op., at 10); see Reply Brief in No. 14–1470, at 5–6. Bernard fails to note the issue that this paragraph addressed. McNeely
concerned only one exception to the usual warrant requirement, the exception for exigent circumstances, and as previously discussed, that exception has always been understood to involve an evaluation of the particular facts of each case. Here, by contrast, we are concerned with the search-incident-to-arrest exception, and as we made clear in Robinson
and repeated in McNeely
itself, this authority is categorical. It does not depend on an evaluation of the threat to officer safety or the threat of evidence loss in a particular case.[7
Having assessed the effect of BAC tests on privacy interests and the need for such tests, we conclude that the Fourth Amendment permits warrantless breath tests incident to arrests for drunk driving. The impact of breath tests on privacy is slight, and the need for BAC testing is great.
We reach a different conclusion with respect to blood tests. Blood tests are significantly more intrusive, and their reasonableness must be judged in light of the availability of the less invasive alternative of a breath test. Respondents have offered no satisfactory justification for demanding the more intrusive alternative without awarrant.
Neither respondents nor their amici
dispute the effectiveness of breath tests in measuring BAC. Breath tests have been in common use for many years. Their results are admissible in court and are widely credited by juries, and respondents do not dispute their accuracy or utility. What, then, is the justification for warrantless blood tests?
One advantage of blood tests is their ability to detect not just alcohol but also other substances that can impair a driver’s ability to operate a car safely. See Brief for New Jersey et al. as Amici Curiae
9; Brief for United States as Amicus Curiae
6. A breath test cannot do this, but police have other measures at their disposal when they have reason to believe that a motorist may be under the influence of some other substance (for example, if a breath test indicates that a clearly impaired motorist has little if any alcohol in his blood). Nothing prevents the police from seeking a warrant for a blood test when there is sufficient time to do so in the particular circumstances or from relying on the exigent circumstances exception to the warrant requirement when there is not. See McNeely
, 569 U. S., at ___–___ (slip op., at 22–23).
A blood test also requires less driver participation than a breath test. In order for a technician to take a blood sample, all that is needed is for the subject to remain still, either voluntarily or by being immobilized. Thus, it is possible to extract a blood sample from a subject who forcibly resists, but many States reasonably prefer not to take this step. See, e.g., Neville
, 459 U. S., at 559–560.
North Dakota, for example, tells us that it generally opposes this practice because of the risk of dangerous altercations between police officers and arrestees in rural areas where the arresting officer may not have backup. Brief for Respondent in No. 14–1468, p. 29. Under current North Dakota law, only in cases involving an accident that results in death or serious injury may blood be taken from arrestees who resist. Compare N. D. Cent. Code Ann. §§39–20–04(1), 39–20–01, with §39–20–01.1.
It is true that a blood test, unlike a breath test, may be administered to a person who is unconscious (perhaps as a result of a crash) or who is unable to do what is needed to take a breath test due to profound intoxication or injuries. But we have no reason to believe that such situations are common in drunk-driving arrests, and when they arise, the police may apply for a warrant if need be.
A breath test may also be ineffective if an arrestee deliberately attempts to prevent an accurate reading by failing to blow into the tube for the requisite length of time or with the necessary force. But courts have held that such conduct qualifies as a refusal to undergo testing, e.g., Andrews
, 52 Ohio St. 2d 31, 36–37, 368 N. E. 2d 1253, 1256–1257 (1977); In re Kunneman
, 501 P. 2d 910, 910–911 (Okla. Civ. App. 1972); see generally 1 Erwin §4.08 (collecting cases), and it may be prosecuted as such. And again, a warrant for a blood test may be sought.
Because breath tests are significantly less intrusive than blood tests and in most cases amply serve law enforcement interests, we conclude that a breath test, but not a blood test, may be administered as a search incident to a lawful arrest for drunk driving. As in all cases involving reasonable searches incident to arrest, a warrant is not needed in this situation.[8
Having concluded that the search incident to arrest doctrine does not justify the warrantless taking of a blood sample, we must address respondents’ alternative argument that such tests are justified based on the driver’s legally implied consent to submit to them. It is well established that a search is reasonable when the subject consents, e.g., Schneckloth
,412 U. S. 218,219 (1973), and that sometimes consent to a search need not be express but may be fairly inferred from context, cf. Florida
,569 U. S. 1, ___–___ (2013) (slip op., at 6–7); Marshall
v. Barlow’s, Inc.
,436 U. S. 307,313 (1978). Our prior opinions have referred approvingly to the general concept of implied-consent laws that impose civil penalties and evidentiary consequences on motorists who refuse to comply. See, e.g., McNeely
, at ___ (plural-ity opinion) (slip op., at 18); Neville
, at 560. Petitioners do not question the constitutionality of those laws, and nothing we say here should be read to cast doubt on them.
It is another matter, however, for a State not only to insist upon an intrusive blood test, but also to impose criminal penalties on the refusal to submit to such a test. There must be a limit to the consequences to which motorists may be deemed to have consented by virtue of a decision to drive on public roads.
Respondents and their amici
all but concede this point. North Dakota emphasizes that its law makes refusal a misdemeanor and suggests that laws punishing refusal more severely would present a different issue. Brief for Respondent in No. 14–1468, at 33–34. Borrowing from our Fifth Amendment jurisprudence, the United States suggests that motorists could be deemed to have consented to only those conditions that are “reasonable” in that they have a “nexus” to the privilege of driving and entail penalties that are proportional to severity of the violation. Brief for United States as Amicus Curiae
21–27. But in the Fourth Amendment setting, this standard does not differ in substance from the one that we apply, since reasonableness is always the touchstone of Fourth Amendment analysis, see Brigham City
,547 U. S. 398,403 (2006). And applying this standard, we conclude that motorists cannot be deemed to have consented to submit to a blood test on pain of committing a criminal offense.
Our remaining task is to apply our legal conclusions to the three cases before us.
Petitioner Birchfield was criminally prosecuted for refusing a warrantless blood draw, and therefore the search he refused cannot be justified as a search incident to his arrest or on the basis of implied consent. There is no indication in the record or briefing that a breath test would have failed to satisfy the State’s interests in acquiring evidence to enforce its drunk-driving laws against Birchfield. And North Dakota has not presented any case-specific information to suggest that the exigent circumstances exception would have justified a warrantless search. Cf. McNeely
, 569 U. S., at ___–___ (slip op., at 20–23). Unable to see any other basis on which to justify a warrantless test of Birchfield’s blood, we conclude that Birchfield was threatened with an unlawful search and that the judgment affirming his conviction must bereversed.
Bernard, on the other hand, was criminally prosecuted for refusing a warrantless breath test. That test was
a permissible search incident to Bernard’s arrest for drunk driving, an arrest whose legality Bernard has not con-tested. Accordingly, the Fourth Amendment did not require officers to obtain a warrant prior to demanding the test, and Bernard had no right to refuse it.
Unlike the other petitioners, Beylund was not prose-cuted for refusing a test. He submitted to a blood test after police told him that the law required his submission, and his license was then suspended and he was fined in an administrative proceeding. The North Dakota Supreme Court held that Beylund’s consent was voluntary on the erroneous assumption that the State could permissibly compel both blood and breath tests. Because voluntariness of consent to a search must be “determined from the totality of all the circumstances,” Schneckloth
, at 227, we leave it to the state court on remand to reevaluate Beylund’s consent given the partial inaccuracy of the officer’s advisory.[9
We accordingly reverse the judgment of the North Da-kota Supreme Court in No. 14–1468 and remand the case for further proceedings not inconsistent with this opinion. We affirm the judgment of the Minnesota Supreme Court in No. 14–1470. And we vacate the judgment of the North Dakota Supreme Court in No. 14–1507 and remand the case for further proceedings not inconsistent with this opinion.
It is so ordered.