(Slip Opinion) OCTOBER TERM, 2015 1 

Syllabus 

NOTE: Where it is feasible, a syllabus (headnote) will be released, as is

being done in connection with this case, at the time the opinion is issued.

The syllabus constitutes no part of the opinion of the Court but has been

prepared by the Reporter of Decisions for the convenience of the reader. 

See United States v. Detroit Timber & Lumber Co., 200 U. S. 321, 337. 

SUPREME COURT OF THE UNITED STATES 

Syllabus 

BIRCHFIELD v. NORTH DAKOTA 

CERTIORARI TO THE SUPREME COURT OF NORTH DAKOTA 

No. 14–1468. Argued April 20, 2016—Decided June 23, 2016* 

To fight the serious harms inflicted by drunk drivers, all States have

laws that prohibit motorists from driving with a blood alcohol concentration (BAC) exceeding a specified level. BAC is typically determined through a direct analysis of a blood sample or by using a machine to measure the amount of alcohol in a person’s breath. To help

secure drivers’ cooperation with such testing, the States have also

enacted “implied consent” laws that require drivers to submit to BAC 

tests. Originally, the penalty for refusing a test was suspension of 

the motorist’s license. Over time, however, States have toughened 

their drunk-driving laws, imposing harsher penalties on recidivists 

and drivers with particularly high BAC levels. Because motorists 

who fear these increased punishments have strong incentives to reject testing, some States, including North Dakota and Minnesota,

now make it a crime to refuse to undergo testing. 

In these cases, all three petitioners were arrested on drunk-driving 

charges. The state trooper who arrested petitioner Danny Birchfield

advised him of his obligation under North Dakota law to undergo 

BAC testing and told him, as state law requires, that refusing to 

submit to a blood test could lead to criminal punishment. Birchfield 

refused to let his blood be drawn and was charged with a misdemeanor violation of the refusal statute. He entered a conditional 

guilty plea but argued that the Fourth Amendment prohibited criminalizing his refusal to submit to the test. The State District Court re-

—————— 

*Together with No. 14–1470, Bernard v. Minnesota, on certiorari to 

the Supreme Court of Minnesota, and No. 14–1507, Beylund v. Levi, 

Director, North Dakota Department of Transportation, also on certiorari 

to the Supreme Court of North Dakota. 
 

 

 

 

 

 

 

2 BIRCHFIELD v. NORTH DAKOTA 

Syllabus 

jected his argument, and the State Supreme Court affirmed. 

After arresting petitioner William Robert Bernard, Jr., Minnesota 

police transported him to the station. There, officers read him Minnesota’s implied consent advisory, which like North Dakota’s informs 

motorists that it is a crime to refuse to submit to a BAC test. Bernard refused to take a breath test and was charged with test refusal 

in the first degree. The Minnesota District Court dismissed the 

charges, concluding that the warrantless breath test was not permitted under the Fourth Amendment. The State Court of Appeals reversed, and the State Supreme Court affirmed. 

The officer who arrested petitioner Steve Michael Beylund took 

him to a nearby hospital. The officer read him North Dakota’s implied consent advisory, informing him that test refusal in these circumstances is itself a crime. Beylund agreed to have his blood 

drawn. The test revealed a BAC level more than three times the legal limit. Beylund’s license was suspended for two years after an

administrative hearing, and on appeal, the State District Court rejected his argument that his consent to the blood test was coerced by 

the officer’s warning. The State Supreme Court affirmed. 

Held: 

1. The Fourth Amendment permits warrantless breath tests incident to arrests for drunk driving but not warrantless blood tests.

Pp. 13–36. 

(a) Taking a blood sample or administering a breath test is a

search governed by the Fourth Amendment. See Skinner v. Railway 

Labor Executives’ Assn., 489 U. S. 602, 616–617; Schmerber v. California, 384 U. S. 757, 767–768. These searches may nevertheless be

exempt from the warrant requirement if they fall within, as relevant 

here, the exception for searches conducted incident to a lawful arrest. 

This exception applies categorically, rather than on a case-by-case 

basis. Missouri v. McNeely, 569 U. S. ___, ___, n. 3. Pp. 14–16.

(b) The search-incident-to-arrest doctrine has an ancient pedigree that predates the Nation’s founding, and no historical evidence 

suggests that the Fourth Amendment altered the permissible bounds

of arrestee searches. The mere “fact of the lawful arrest” justifies “a

full search of the person.” United States v. Robinson, 414 U. S. 218, 

235. The doctrine may also apply in situations that could not have

been envisioned when the Fourth Amendment was adopted. In Riley 

v. California, 573 U. S. ___, the Court considered how to apply the 

doctrine to searches of an arrestee’s cell phone. Because founding era 

guidance was lacking, the Court determined “whether to exempt [the] 

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 legit-
 

 

 

 

 

 

 

 

Cite as: 579 U. S. ____ (2016) 3 

Syllabus 

imate governmental interests.’ ” Id., at ___. The same mode of analysis is proper here because the founding era provides no definitive

guidance on whether blood and breath tests should be allowed incident to arrest. Pp. 16–20.

(c) The analysis begins by considering the impact of breath and 

blood tests on individual privacy interests. Pp. 20–23.

(1) Breath tests do not “implicat[e] significant privacy concerns.” Skinner, 489 U. S., at 626. The physical intrusion is almost 

negligible. The tests “do not require piercing the skin” and entail “a

minimum of inconvenience.” Id., at 625. Requiring an arrestee to insert the machine’s mouthpiece into his or her mouth and to exhale 

“deep lung” air is no more intrusive than collecting a DNA sample by

rubbing a swab on the inside of a person’s cheek, Maryland v. King, 

569 U. S. ___, ___, or scraping underneath a suspect’s fingernails, 

Cupp v. Murphy, 412 U. S. 291. Breath tests, unlike DNA samples,

also yield only a BAC reading and leave no biological sample in the

government’s possession. Finally, participation in a breath test is not

likely to enhance the embarrassment inherent in any arrest. Pp. 20– 

22. 

(2) The same cannot be said about blood tests. They “require

piercing the skin” and extract a part of the subject’s body, Skinner, 

supra, at 625, and thus are significantly more intrusive than blowing 

into a tube. A blood test also gives law enforcement a sample that

can be preserved and from which it is possible to extract information

beyond a simple BAC reading. That prospect could cause anxiety for 

the person tested. Pp. 22–23. 

(d) The analysis next turns to the States’ asserted need to obtain

BAC readings. Pp. 23–33.

(1) The States and the Federal Government have a “paramount

interest . . . in preserving [public highway] safety,” Mackey v. 

Montrym, 443 U. S. 1, 17; and States have a compelling interest in 

creating “deterrent[s] to drunken driving,” a leading cause of traffic

fatalities and injuries, id., at 18. Sanctions for refusing to take a

BAC test were increased because consequences like license suspension were no longer adequate to persuade the most dangerous offenders to agree to a test that could lead to severe criminal sanctions. By

making it a crime to refuse to submit to a BAC test, the laws at issue

provide an incentive to cooperate and thus serve a very important

function. Pp. 23–25.

(2) As for other ways to combat drunk driving, this Court’s decisions establish that an arresting officer is not obligated to obtain a

warrant before conducting a search incident to arrest simply because 

there might be adequate time in the particular circumstances to obtain a warrant. The legality of a search incident to arrest must be 
 

 

 

 

 

4 BIRCHFIELD v. NORTH DAKOTA 

Syllabus 

judged on the basis of categorical rules. See e.g., Robinson, supra, at 

235. McNeely, supra, at ___, distinguished. Imposition of a warrant 

requirement for every BAC test would likely swamp courts, given the 

enormous number of drunk-driving arrests, with little corresponding 

benefit. And other alternatives—e.g., sobriety checkpoints and ignition interlock systems—are poor substitutes. Pp. 25–30.

(3) Bernard argues that warrantless BAC testing cannot be

justified as a search incident to arrest because that doctrine aims to 

prevent the arrestee from destroying evidence, while the loss of blood

alcohol evidence results from the body’s metabolism of alcohol, a natural process not controlled by the arrestee. In both instances, however, the State is justifiably concerned that evidence may be lost. The 

State’s general interest in “evidence preservation” or avoiding “the 

loss of evidence,” Riley, supra, at ___, readily encompasses the metabolization of alcohol in the blood. Bernard’s view finds no support 

in Chimel v. California, 395 U. S. 752, 763, Schmerber, 384 U. S., at 

769, or McNeely, supra, at ___. Pp. 30–33.

(e) Because the impact of breath tests on privacy is slight, and 

the need for BAC testing is great, the Fourth Amendment permits

warrantless breath tests incident to arrests for drunk driving. Blood 

tests, however, 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 a 

warrant. In instances where blood tests might be preferable—e.g.,

where substances other than alcohol impair the driver’s ability to operate a car safely, or where the subject is unconscious—nothing prevents the police from seeking a warrant or from relying on the exigent circumstances exception if it applies. Because breath tests are 

significantly less intrusive than blood tests and in most cases amply

serve law enforcement interests, a breath test, but not a blood test, 

may be administered as a search incident to a lawful arrest for drunk

driving. No warrant is needed in this situation. Pp. 33–35.

2. Motorists may not be criminally punished for refusing to submit

to a blood test based on legally implied consent to submit to them. It 

is one thing to approve implied-consent laws that impose civil penalties and evidentiary consequences on motorists who refuse to comply, 

but quite another for a State to insist upon an intrusive blood test

and then to impose criminal penalties on refusal to submit. 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. Pp. 36–37.

3. These legal conclusions resolve the three present cases. Birchfield was criminally prosecuted for refusing a warrantless blood 
 

Cite as: 579 U. S. ____ (2016) 5 

Syllabus 

draw, and therefore the search that he refused cannot be justified as 

a search incident to his arrest or on the basis of implied consent. Because there appears to be no other basis for a warrantless test of

Birchfield’s blood, he was threatened with an unlawful search and 

unlawfully convicted for refusing that search. Bernard was criminally prosecuted for refusing a warrantless breath test. Because that 

test was a permissible search incident to his arrest for drunk driving,

the Fourth Amendment did not require officers to obtain a warrant

prior to demanding the test, and Bernard had no right to refuse it.

Beylund submitted to a blood test after police told him that the law

required his submission. The North Dakota Supreme Court, which 

based its conclusion that Beylund’s consent was voluntary on the erroneous assumption that the State could compel blood tests, should

reevaluate Beylund’s consent in light of the partial inaccuracy of the 

officer’s advisory. Pp. 37–38. 

No. 14–1468, 2015 ND 6, 858 N. W. 2d 302, reversed and remanded; 

No. 14–1470, 859 N. W. 2d 762, affirmed; No. 14–1507, 2015 ND 18, 

859 N. W. 2d 403, vacated and remanded. 

ALITO, J., delivered the opinion of the Court, in which ROBERTS, C. J, 

and KENNEDY, BREYER, and KAGAN, JJ., joined. SOTOMAYOR, J., filed an 

opinion concurring in part and dissenting in part, in which GINSBURG, 

J., joined. THOMAS, J., filed an opinion concurring in the judgment in

part and dissenting in part. 
 

 

_________________ 

_________________ 

Cite as: 579 U. S. ____ (2016) 1 

Opinion of the Court 

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 

14–1468 v. 

NORTH DAKOTA; 

ON WRIT OF CERTIORARI TO THE SUPREME COURT OF
 

NORTH DAKOTA
 

WILLIAM ROBERT BERNARD, JR., PETITIONER 

14–1470 v. 

MINNESOTA; AND 

ON WRIT OF CERTIORARI TO THE SUPREME COURT OF
 

MINNESOTA
 

STEVE MICHAEL BEYLUND, PETITIONER 

14–1507 v. 

GRANT LEVI, DIRECTOR, NORTH DAKOTA 

DEPARTMENT OF TRANSPORTATION 

ON WRIT OF CERTIORARI TO THE SUPREME COURT OF
 

NORTH 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 
 

2 BIRCHFIELD v. NORTH DAKOTA 

Opinion of the Court 

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. 

I 

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 drunkdriving 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 
Cite as: 579 U. S. ____ (2016) 3 

Opinion of the Court 

necessary for some witness to prove that some one or more 

of these effects were perceptible to him.” State v. Noble, 

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%. Donigan 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 v. Neville, 
 

 

 

4 BIRCHFIELD v. NORTH DAKOTA 

Opinion of the Court 

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., at 303. 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[7] (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 v. Trombetta, 467 U. S. 479, 489 (1984). 
Cite as: 579 U. S. ____ (2016) 5 

Opinion of the Court 

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, supra, at 481; 

see also 2 Erwin §21.04[2][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, supra, 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[2][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[2], 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 
 

 

6 BIRCHFIELD v. NORTH DAKOTA 

Opinion of the Court 

States to find a way of securing such cooperation.1 Socalled “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 drunkdriving offense.” Missouri v. McNeely, 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 alcoholrelated 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 

—————— 

1 In addition, BAC may be determined by testing a subject’s urine,

which also requires the test subject’s cooperation. But urine tests 

appear to be less common in drunk-driving cases than breath and blood

tests, and none of the cases before us involves one. 
 

 

 

 

Cite as: 579 U. S. ____ (2016) 7 

Opinion of the Court 

legal change has been further lowering the BAC standard 

from 0.10% to 0.08%. See 1 Erwin, §2.01[1], 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 
 

8 BIRCHFIELD v. NORTH DAKOTA 

Opinion of the Court 

(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. 

II
 

A 

 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 

—————— 

2See Smith, Moving From Grief to Action: Two Families Push for 

Stronger DUI Laws in N. D., Bismarck Tribune, Feb. 2, 2013, p. 1A;

Haga, Some Kind of Peace: Parents of Two Young Boys Killed in

Campground Accident Urge for Tougher DUI Penalties in N. D., Grand 

Forks Herald, Jan. 15, 2013, pp. A1–A2. 
Cite as: 579 U. S. ____ (2016) 9 

Opinion of the Court 

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[1]. 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 v. Birchfield, Crim. No. 30– 

2013–CR–00720 (Dist. Ct. Morton Cty., N. D., Jan. 27, 

2014). This time he also pleaded guilty—to a misdemeanor violation of the refusal statute—but his plea was

a 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 
 

 

10 BIRCHFIELD v. NORTH DAKOTA 

Opinion of the Court 

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)). 

B 

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 offend­
 

Cite as: 579 U. S. ____ (2016) 11 

Opinion of the Court 

ers, §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.). 

C 

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 
 

12 BIRCHFIELD v. NORTH DAKOTA 

Opinion of the Court 

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 v. Smith, 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., 

at 606. 

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. 
 

Cite as: 579 U. S. ____ (2016) 13 

Opinion of the Court 

III 

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. 
 

 

 

 

14 BIRCHFIELD v. NORTH DAKOTA 

Opinion of the Court 

IV 

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 sample or the administration of a breath test is a search.

See Skinner v. Railway Labor Executives’ Assn., 489 U. S. 

602, 616–617 (1989); Schmerber v. California, 384 U. S. 

757, 767–768 (1966). The question, then, is whether the 

warrantless searches at issue here were reasonable. See 

Vernonia School Dist. 47J v. Acton, 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 v. 

King, 563 U. S. 452, 459 (2011); see also California v. 

Acevedo, 500 U. S. 565, 581 (1991) (Scalia, J., concurring in judgment) (“What [the text] explicitly states regarding 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 circumstances exception allows a warrantless search when an 

emergency leaves police insufficient time to seek a warrant. 
Cite as: 579 U. S. ____ (2016) 15 

Opinion of the Court 

Michigan v. Tyler, 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, supra, at 460. 

In Schmerber v. California, 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., at 770–772. 

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 v. McNeely, 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 
 

 

 

 

 

 

16 BIRCHFIELD v. NORTH DAKOTA 

Opinion of the Court 

op., at 9).

While emphasizing that the exigent-circumstances

exception must be applied on a case-by-case basis, the 

McNeely Court noted that other exceptions to the warrant

requirement “apply categorically” rather than in a “casespecific” fashion. Id., at ___, n. 3 (slip op., at 7, n. 3). One 

of these, as the McNeely opinion recognized, is the longestablished 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. 

V 

A 

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 
 

Cite as: 579 U. S. ____ (2016) 17 

Opinion of the Court 

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 v. Hennessey, 141 Mo. 527, 539– 

540, 42 S. W. 1090, 1093 (1897); Ex parte Hurn, 92 Ala. 

102, 112, 9 So. 515, 519 (1891); Thatcher v. Weeks, 79 Me. 

547, 548–549, 11 A. 599 (1887); Reifsnyder v. Lee, 44 Iowa 

101, 103 (1876); F. Wharton, Criminal Pleading and Prac­
 

18 BIRCHFIELD v. NORTH DAKOTA 

Opinion of the Court 

tice §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 v. Lefkowitz, 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 v. Rabinowitz, 339 U. S. 56, 60–65 (1950) (permitting complete

search of arrestee’s office).

We attempted to clarify the law regarding searches

incident to arrest in Chimel v. California, 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 v. Robinson, 414 U. S. 

218 (1973), we elaborated on Chimel’s meaning. We noted 

that the search-incident-to-arrest rule actually comprises 
Cite as: 579 U. S. ____ (2016) 19 

Opinion of the Court 

“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. 

In Robinson itself, that meant that police had acted permissibly in searching inside a package of cigarettes found 

on the man they arrested. Id., at 236. 

Our decision two Terms ago in Riley v. California, 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, 
 

20 BIRCHFIELD v. NORTH DAKOTA 

Opinion of the Court 

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. 

B 

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. 

1 

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 

—————— 

3At most, there may be evidence that an arrestee’s mouth could be 

searched in appropriate circumstances at the time of the founding. See 

W. Cuddihy, Fourth Amendment: Origins and Original Meaning: 602–

1791, p. 420 (2009). Still, searching a mouth for weapons or contraband 

is not the same as requiring an arrestee to give up breath or blood. 
Cite as: 579 U. S. ____ (2016) 21 

Opinion of the Court 

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 generally 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 v. King, 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 v. Murphy, 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 v. King. 

Although the DNA obtained under the law at issue in that 

case could lawfully be used only for identification pur- 
 

 

22 BIRCHFIELD v. NORTH DAKOTA 

Opinion of the Court 

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, supra, 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 v. King, 

supra, 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. 

2 

Blood tests are a different matter. They “require piercing the skin” and extract a part of the subject’s body. 

Skinner, supra, 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. 
 

Cite as: 579 U. S. ____ (2016) 23 

Opinion of the Court 

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. 

C 

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. 

1 

The States and the Federal Government have a “paramount interest . . . in preserving the safety of . . . public 

highways.” Mackey v. Montrym, 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). 
 

24 BIRCHFIELD v. NORTH DAKOTA 

Opinion of the Court 

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 AlcoholImpaired 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 v. Abram, 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, supra, at 18. 

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 
 

Cite as: 579 U. S. ____ (2016) 25 

Opinion of the Court 

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. 

2 

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 
 

26 BIRCHFIELD v. NORTH DAKOTA 

Opinion of the Court 

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 did not 

explain how to apply an existing exception, let alone the 

long-established exception for searches incident to a lawful 

arrest, whose applicability, as Robinson and Riley 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-bycase exigent circumstances doctrine are actually parts of a

single framework, post, at 6–7, and n. 3, in McNeely the 
Cite as: 579 U. S. ____ (2016) 27 

Opinion of the Court 

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 marijuana 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 
 

 

 

28 BIRCHFIELD v. NORTH DAKOTA 

Opinion of the Court 

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 drunkdriving 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-toarrest 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 v. Chadwick, 433 U. S. 1, 9 (1977), 

—————— 

4See North Dakota Supreme Court, All District Judges, http://

www.ndcourts.gov/court/districts/judges.htm (all Internet materials as

last visited June 21, 2016). 5See North Dakota Supreme Court, Magistrates, http://www.ndcourts.gov/

court/counties/magistra/members.htm. 6North Dakota Supreme Court justices apparently also have authority to issue warrants statewide. See ND Op. Atty. Gen. 99–L–132, p. 2 

(Dec. 30, 1999). But we highly doubt that they regularly handle searchwarrant applications, much less during graveyard shifts. 
 

Cite as: 579 U. S. ____ (2016) 29 

Opinion of the Court 

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 
 

 

30 BIRCHFIELD v. NORTH DAKOTA 

Opinion of the Court 

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. 

3 

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 
 

 

Cite as: 579 U. S. ____ (2016) 31 

Opinion of the Court 

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 v. Iowa, 525 U. S. 113, 118–119 

(1998) (“the need to discover and preserve evidence;” “the

concern for destruction or loss of evidence” (emphasis

added)); Virginia v. Moore, 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 chem­
 

32 BIRCHFIELD v. NORTH DAKOTA 

Opinion of the Court 

ical 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. Although the Court appreciated as well that blood tests “involv[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 said nothing.

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 
 

 

 

Cite as: 579 U. S. ____ (2016) 33 

Opinion of the Court 

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 a 

warrant. 

Neither respondents nor their amici dispute the effec­

—————— 

7 JUSTICE SOTOMAYOR objects to treating warrantless breath tests as

searches incident to a lawful arrest on two additional grounds. 

First, she maintains that “[a]ll of this Court’s postarrest exceptions to

the warrant requirement require a law enforcement interest separate 

from criminal investigation.” Post, at 14. At least with respect to the 

search-incident-to-arrest doctrine, that is not true. As the historical 

authorities discussed earlier attest, see Part V–A, supra, the doctrine 

has always been understood as serving investigative ends, such as

“discover[ing] and seiz[ing] . . . evidences of crime.” Weeks v. United 

States, 232 U. S. 383, 392 (1914); see also United States v. Robinson, 

414 U. S. 218, 235 (1973) (emphasizing “the need . . . to discover evidence”). Using breath tests to obtain evidence of intoxication is therefore well within the historical understanding of the doctrine’s purposes. 

 Second, JUSTICE SOTOMAYOR contends that the search-incident-toarrest doctrine does not apply when “a narrower exception to the 

warrant requirement adequately satisfies the governmental needs

asserted.” Post, at 7, n. 3; see also post, at 17–19. But while this 

Court’s cases have certainly recognized that “more targeted” exceptions

to the warrant requirement may justify a warrantless search even 

when the search-incident-to-arrest exception would not, Riley v. California, 573 U. S. ___, ___ (2014) (slip op., at 14), JUSTICE SOTOMAYOR 

cites no authority for the proposition that an exception to the warrant

requirement cannot apply simply because a “narrower” exception might 

apply. 
 

 

34 BIRCHFIELD v. NORTH DAKOTA 

Opinion of the Court 

tiveness 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. 
 

 

Cite as: 579 U. S. ____ (2016) 35 

Opinion of the Court 

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 v. Turner, 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[2] (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 

—————— 

8 JUSTICE THOMAS partly dissents from this holding, calling any distinction between breath and blood tests “an arbitrary line in the sand.” 

Post, at 3 (opinion concurring in judgment in part and dissenting in 

part). Adhering to a position that the Court rejected in McNeely, 

JUSTICE THOMAS would hold that both breath and blood tests are 

constitutional with or without a warrant because of the natural metabolization of alcohol in the bloodstream. Post, at 3–5. Yet JUSTICE 

THOMAS does not dispute our conclusions that blood draws are more 

invasive than breath tests, that breath tests generally serve state 

interests in combating drunk driving as effectively as blood tests, and 

that our decision in Riley calls for a balancing of individual privacy

interests and legitimate state interests to determine the reasonableness 
 

 

 

36 BIRCHFIELD v. NORTH DAKOTA 

Opinion of the Court 

VI 

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 v. Bustamonte, 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 v. Jardines, 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, supra, at ___ (plurality opinion) (slip op., at 18); Neville, supra, 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 

—————— 

of the category of warrantless search that is at issue. Contrary to 

JUSTICE THOMAS’s contention, this balancing does not leave law enforcement officers or lower courts with unpredictable rules, because it is 

categorical and not “case-by-case,” post, at 3. Indeed, today’s decision

provides very clear guidance that the Fourth Amendment allows

warrantless breath tests, but as a general rule does not allow warrantless blood draws, incident to a lawful drunk-driving arrest. 
 

Cite as: 579 U. S. ____ (2016) 37 

Opinion of the Court 

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 v. Stuart, 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. 

VII 

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 casespecific 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 be

reversed. 

Bernard, on the other hand, was criminally prosecuted 
 

38 BIRCHFIELD v. NORTH DAKOTA 

Opinion of the Court 

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 contested. 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 prosecuted 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, supra, 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 Dakota 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. 

—————— 

9 If the court on remand finds that Beylund did not voluntarily consent, it will have to address whether the evidence obtained in the 

search must be suppressed when the search was carried out pursuant 

to a state statute, see Heien v. North Carolina, 574 U. S. ___, ___–___ 

(2014) (slip op., at 8–10), and the evidence is offered in an administrative rather than criminal proceeding, see Pennsylvania Bd. of Probation 

and Parole v. Scott, 524 U. S. 357, 363–364 (1998). And as Beylund

notes, remedies may be available to him under state law. See Brief for 

Petitioner in No. 14–1507, pp. 13–14. 
_________________ 

_________________ 

Cite as: 579 U. S. ____ (2016) 1 

Opinion of SOTOMAYOR, J. 

SUPREME COURT OF THE UNITED STATES 

Nos. 14–1468, 14–1470, and 14–1507 

DANNY BIRCHFIELD, PETITIONER 

14–1468 v. 

NORTH DAKOTA; 

ON WRIT OF CERTIORARI TO THE SUPREME COURT OF
 

NORTH DAKOTA
 

WILLIAM ROBERT BERNARD, JR., PETITIONER 

14–1470 v. 

MINNESOTA; AND 

ON WRIT OF CERTIORARI TO THE SUPREME COURT OF
 

MINNESOTA
 

STEVE MICHAEL BEYLUND, PETITIONER 

14–1507 v. 

GRANT LEVI, DIRECTOR, NORTH DAKOTA 

DEPARTMENT OF TRANSPORTATION 

ON WRIT OF CERTIORARI TO THE SUPREME COURT OF
 

NORTH DAKOTA
 

[June 23, 2016] 

JUSTICE SOTOMAYOR, with whom JUSTICE GINSBURG 

joins, concurring in part and dissenting in part. 

The Court today considers three consolidated cases. I 

join the majority’s disposition of Birchfield v. North Dakota, No. 14–1468, and Beylund v. Levi, No. 14–1507, in 

which the Court holds that the search-incident-to-arrest 

exception to the Fourth Amendment’s warrant requirement does not permit warrantless blood tests. But I dis-
 

2 BIRCHFIELD v. NORTH DAKOTA 

Opinion of SOTOMAYOR, J. 

sent from the Court’s disposition of Bernard v. Minnesota, 

No. 14–1470, in which the Court holds that the same 

exception permits warrantless breath tests. Because no 

governmental interest categorically makes it impractical 

for an officer to obtain a warrant before measuring a 

driver’s alcohol level, the Fourth Amendment prohibits 

such searches without a warrant, unless exigent circumstances exist in a particular case.1 

I 

A 

As the Court recognizes, the proper disposition of this 

case turns on whether the Fourth Amendment guarantees

a right not to be subjected to a warrantless breath test

after being arrested. 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 “ultimate touchstone of the Fourth Amendment is 

‘reasonableness.’” Brigham City v. Stuart, 547 U. S. 398, 

403 (2006). A citizen’s Fourth Amendment right to be free 

from “unreasonable searches” does not disappear upon 

arrest. Police officers may want to conduct a range of

searches after placing a person under arrest. They may

want to pat the arrestee down, search her pockets and

purse, peek inside her wallet, scroll through her cellphone, 

examine her car or dwelling, swab her cheeks, or take 

—————— 

1Because I see no justification for warrantless blood or warrantless

breath tests, I also dissent from the parts of the majority opinion that 

justify its conclusions with respect to blood tests on the availability of 

warrantless breath tests. See ante, at 33-34. 
 

 

Cite as: 579 U. S. ____ (2016) 3 

Opinion of SOTOMAYOR, J. 

blood and breath samples to determine her level of intoxication. But an officer is not authorized to conduct all of 

these searches simply because he has arrested someone.

Each search must be separately analyzed to determine its

reasonableness. 

Both before and after a person has been arrested, warrants are the usual safeguard against unreasonable

searches because they guarantee that the search is not a

“random or arbitrary ac[t] of government agents,” but is

instead “narrowly limited in its objectives and scope.” 

Skinner v. Railway Labor Executives’ Assn., 489 U. S. 602, 

622 (1989). Warrants provide the “detached scrutiny of a

neutral magistrate, and thus ensur[e] an objective determination whether an intrusion is justified.” Ibid. And 

they give life to our instruction that the Fourth Amendment “is designed to prevent, not simply to redress, unlawful police action.” Steagald v. United States, 451 U. S. 

204, 215 (1981) (internal quotation marks omitted).

Because securing a warrant before a search is the rule of 

reasonableness, the warrant requirement is “subject only 

to a few specifically established and well-delineated exceptions.” Katz v. United States, 389 U. S. 347, 357 (1967).

To determine whether to “exempt a given type of search

from the warrant requirement,” this Court traditionally 

“assess[es], 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.” Riley v. California, 573 

U. S. ___, ___ (2014) (slip op., at 9) (internal quotation 

marks omitted). In weighing “whether the public interest

demands creation of a general exception to the Fourth 

Amendment’s warrant requirement, the question is not 

whether the public interest justifies the type of search in

question,” but, more specifically, “whether the burden of 

obtaining a warrant is likely to frustrate the governmental 

purpose behind the search.” Camara v. Municipal Court 
 

 

 

 

4 BIRCHFIELD v. NORTH DAKOTA 

Opinion of SOTOMAYOR, J. 

of City and County of San Francisco, 387 U.S. 523, 533 

(1967); see also Almeida-Sanchez v. United States, 413 

U. S. 266, 282–283 (1973) (Powell, J., concurring) (noting 

that in areas ranging from building inspections to automobile searches, the Court’s “general approach to exceptions to the warrant requirement” is to determine whether

a “‘warrant system can be constructed that would be

feasible and meaningful’”); United States v. United States 

Dist. Court for Eastern Dist. of Mich., 407 U. S. 297, 315 

(1972) (“We must . . . ask whether a warrant requirement

would unduly frustrate the [governmental interest]”).2 

Applying these principles in past cases, this Court has

recognized two kinds of exceptions to the warrant requirement that are implicated here: (1) case-by-case exceptions, where the particularities of an individual case 

justify a warrantless search in that instance, but not

others; and (2) categorical exceptions, where the commonalities among a class of cases justify dispensing with the 

warrant requirement for all of those cases, regardless of

their individual circumstances. 

Relevant here, the Court allows warrantless searches on 

a case-by-case basis where the “exigencies” of the particular case “make the needs of law enforcement so compelling 

that a warrantless search is objectively reasonable” in that 

—————— 

2The Court is wrong to suggest that because the States are seeking 

an extension of the “existing” search-incident-to-arrest exception rather 

than the “creation” of a new exception for breath searches, this Court 

need not determine whether the governmental interest in these searches

can be accomplished without excusing the warrant requirement. Ante, 

at 26. To the contrary, as the very sentence the Court cites illustrates, the question is always whether the particular “type of

search in question” is reasonable if conducted without a warrant. 

Camara, 387 U. S., at 533. To answer that question, in every case, 

courts must ask whether the “burden of obtaining a warrant is likely to

frustrate the governmental purpose behind the search.” Ibid. This 

question may be answered based on existing doctrine, or it may require 

the creation of new doctrine, but it must always be asked. 
 

Cite as: 579 U. S. ____ (2016) 5 

Opinion of SOTOMAYOR, J. 

instance. Missouri v. McNeely, 569 U. S. ___, ___ (2013) 

(slip op., at 5) (quoting Kentucky v. King, 563 U. S. 452, 

460 (2011)). The defining feature of the exigent circumstances exception is that the need for the search becomes

clear only after “all of the facts and circumstances of the

particular case” have been considered in light of the “totality of the circumstances.” 569 U. S., at ___ (slip op., at 8). 

Exigencies can include officers’ “need to provide emergency assistance to an occupant of a home, engage in ‘hot 

pursuit’ of a fleeing suspect, or enter a burning building to 

put out a fire and investigate its cause.” Id., at ___ (slip 

op., at 5) (citations omitted).

Exigencies can also arise in efforts to measure a driver’s

blood alcohol level. In Schmerber v. California, 384 U. S. 

757 (1966), for instance, a man sustained injuries in a car 

accident and was transported to the hospital. While there, 

a police officer arrested him for drunk driving and ordered 

a warrantless blood test to measure his blood alcohol 

content. This Court noted that although the warrant 

requirement generally applies to postarrest blood tests, a

warrantless search was justified in that case because 

several hours had passed while the police investigated the 

scene of the crime and Schmerber was taken to the hospital, precluding a timely securing of a warrant. Id., at 770– 

771. 

This Court also recognizes some forms of searches in

which the governmental interest will “categorically” outweigh the person’s privacy interest in virtually any circumstance in which the search is conducted. Relevant 

here is the search-incident-to-arrest exception. That 

exception allows officers to conduct a limited postarrest

search without a warrant to combat risks that could arise 

in any arrest situation before a warrant could be obtained: 

“‘to remove any weapons that the [arrestee] might seek to

use in order to resist arrest or effect his escape’” and to 

“‘seize any evidence on the arrestee’s person in order to 
 

6 BIRCHFIELD v. NORTH DAKOTA 

Opinion of SOTOMAYOR, J. 

prevent its concealment or destruction.’” Riley, 573 U. S., 

at ___ (slip op., at 6) (quoting Chimel v. California, 395 

U. S. 752, 763 (1969)). That rule applies “categorical[ly]” 

to all arrests because the need for the warrantless search 

arises from the very “fact of the lawful arrest,” not from

the reason for arrest or the circumstances surrounding it. 

United States v. Robinson, 414 U. S. 218, 225, 235 (1973).

Given these different kinds of exceptions to the warrant

requirement, if some form of exception is necessary for a

particular kind of postarrest search, the next step is to ask 

whether the governmental need to conduct a warrantless

search arises from “threats” that “‘lurk in all custodial 

arrests’” and therefore “justif[ies] dispensing with the 

warrant requirement across the board,” or, instead, 

whether the threats “may be implicated in a particular

way in a particular case” and are therefore “better addressed through consideration of case-specific exceptions 

to the warrant requirement, such as the one for exigent

circumstances.” Riley, 573 U. S., at ___ (slip op., at 11–12) 

(alterations and internal quotation marks omitted).

To condense these doctrinal considerations into a 

straightforward rule, the question is whether, in light of 

the individual’s privacy, a “legitimate governmental interest” justifies warrantless searches—and, if so, whether 

that governmental interest is adequately addressed by a 

case-by-case exception or requires by its nature a categorical exception to the warrant requirement. 

B 

This Court has twice applied this framework in recent 

terms. Riley v. California, 573 U. S. ___,addressed whether, 

after placing a person under arrest, a police officer may

conduct a warrantless search of his cell phone data. California asked for a categorical rule, but the Court rejected

that request, concluding that cell phones do not present 

the generic arrest-related harms that have long justified 
 

Cite as: 579 U. S. ____ (2016) 7 

Opinion of SOTOMAYOR, J. 

the search-incident-to-arrest exception. The Court found 

that phone data posed neither a danger to officer safety

nor a risk of evidence destruction once the physical phone

was secured. Id., at ___–___ (slip op., at 10–15). The 

Court nevertheless acknowledged that the exigent circumstances exception might be available in a “now or never

situation.” Id., at ___ (slip op., at 15) (internal quotation 

marks omitted). It emphasized that “[i]n light of the

availability of the exigent circumstances exception, there

is no reason to believe that law enforcement officers will 

not be able to address” the rare needs that would require 

an on-the-spot search. Id., at ___ (slip op., at 26). 

Similarly, Missouri v. McNeely, 569 U. S. ___,applied 

this doctrinal analysis to a case involving police efforts to

measure drivers’ blood alcohol levels. In that case, Missouri argued that the natural dissipation of alcohol in a

person’s blood justified a per se exigent circumstances

exception to the warrant requirement—in essence, a new 

kind of categorical exception. The Court recognized that 

exigencies could exist, like in Schmerber, that would justify warrantless searches. 569 U. S., at ___ (slip op., at 9). 

But it also noted that in many drunk driving situations,

no such exigencies exist. Where, for instance, “the warrant process will not significantly increase the delay” in

testing “because an officer can take steps to secure a warrant” while the subject is being prepared for the test, there

is “no plausible justification for an exception to the warrant requirement.” Id., at ___ (slip op., at 10). The Court 

thus found it unnecessary to “depart from careful case-bycase assessment of exigency and adopt the categorical rule

proposed by the State.” Id., at ___ (slip op., at 9).3 

—————— 

3The Court quibbles with our unremarkable statement that the categorical search-incident-to-arrest doctrine and the case-by-case exigent

circumstances doctrine are part of the same framework by arguing that

a footnote in McNeely was “careful to note that the decision did not 

address any other exceptions to the warrant requirement.” Ante, at 26-
 

 

8 BIRCHFIELD v. NORTH DAKOTA 

Opinion of SOTOMAYOR, J. 

II 

The States do not challenge McNeely’s holding that a

categorical exigency exception is not necessary to accommodate the governmental interests associated with the

dissipation of blood alcohol after drunk-driving arrests.

They instead seek to exempt breath tests from the warrant requirement categorically under the search-incidentto-arrest doctrine. The majority agrees. Both are wrong.

As discussed above, regardless of the exception a State

requests, the Court’s traditional framework asks whether,

in light of the privacy interest at stake, a legitimate gov-

—————— 

27 (citing McNeely, 569 U. S., at ___, n. 3 (slip op., at 7, n. 3)). That 

footnote explains the difference between categorical exceptions and 

case-by-case exceptions generally. Id., at ___, n. 3. It does nothing to

suggest that the two forms of exceptions should not be considered

together when analyzing whether it is reasonable to exempt categorically a particular form of search from the Fourth Amendment’s warrant 

requirement.

It should go without saying that any analysis of whether to apply a 

Fourth Amendment warrant exception must necessarily be comparative. If a narrower exception to the warrant requirement adequately

satisfies the governmental needs asserted, a more sweeping exception

will be overbroad and could lead to unnecessary and “unreasonable

searches” under the Fourth Amendment. Contrary to the Court’s

suggestion that “no authority” supports this proposition, see ante, at 33 

n. 8, our cases have often deployed this commonsense comparative 

check. See Riley v. California, 573 U. S. ___, ___–___ (2014) (slip op., at

14–15) (rejecting the application of the search-incident-to-arrest exception because the exigency exception is a “more targeted wa[y] to address [the government’s] concerns”); id., at ___ (slip op., at 11) (analyzing whether the governmental interest can be “better addressed 

through consideration of case-specific exceptions to the warrant requirement”); id., at __ (slip op., at 26–27) (noting that “[i]n light of the

availability of the exigent circumstances exception, there is no reason

to believe that” the governmental interest cannot be satisfied without a

categorical search-incident-to-arrest exception); McNeely, 569 U. S., at 

___ (slip op., at 9–10) (holding that the availability of the exigency

exception for circumstances that “make obtaining a warrant impractical” is “reason . . . not to accept the ‘considerable overgeneralization’

that a per se rule would reflect”). 
Cite as: 579 U. S. ____ (2016) 9 

Opinion of SOTOMAYOR, J. 

ernmental interest ever requires conducting breath 

searches without a warrant—and, if so, whether that 

governmental interest is adequately addressed by a caseby-case exception or requires a categorical exception to the 

warrant requirement. That framework directs the conclusion that a categorical search-incident-to-arrest rule for 

breath tests is unnecessary to address the States’ governmental interests in combating drunk driving. 

A 

Beginning with the governmental interests, there can be

no dispute that States must have tools to combat drunk 

driving. See ante, at 2–8. But neither the States nor the 

Court has demonstrated that “obtaining a warrant” in

cases not already covered by the exigent circumstances

exception “is likely to frustrate the governmental purpose[s] behind [this] search.” Camara, 387 U. S., at 533.4 

First, the Court cites the governmental interest in protecting the public from drunk drivers. See ante, at 24. 

But it is critical to note that once a person is stopped for 

drunk driving and arrested, he no longer poses an immediate threat to the public. Because the person is already

in custody prior to the administration of the breath test,

there can be no serious claim that the time it takes to 

obtain a warrant would increase the danger that drunk 

driver poses to fellow citizens.

Second, the Court cites the governmental interest in

preventing the destruction or loss of evidence. See ante, at 

30-31. But neither the Court nor the States identify any 

practical reasons why obtaining a warrant after making

an arrest and before conducting a breath test compromises 

the quality of the evidence obtained. To the contrary, the

delays inherent in administering reliable breath tests 

—————— 

4Although Bernard’s case arises in Minnesota, North Dakota’s similar breath test laws are before this Court. I therefore consider both 

States together. 
 

10 BIRCHFIELD v. NORTH DAKOTA 

Opinion of SOTOMAYOR, J. 

generally provide ample time to obtain a warrant. 

There is a common misconception that breath tests are 

conducted roadside, immediately after a driver is arrested. 

While some preliminary testing is conducted roadside, 

reliability concerns with roadside tests confine their use in 

most circumstances to establishing probable cause for an 

arrest. See 2 R. Erwin, Defense of Drunk Driving Cases 

§18.08 (3d ed. 2015) (“Screening devices are . . . used when 

it is impractical to utilize an evidential breath tester

(EBT) (e.g. at roadside or at various work sites)”). The 

standard evidentiary breath test is conducted after a 

motorist is arrested and transported to a police station, 

governmental building, or mobile testing facility where 

officers can access reliable, evidence-grade breath testing

machinery. Brief for Respondent in No. 14–1618, p. 8, 

n. 2; National Highway Transportation Safety Admin. 

(NHTSA), A. Berning et al., Refusal of Intoxication Testing: A Report to Congress 4, and n. 5 (No. 811098, Sept.

2008). Transporting the motorist to the equipment site is 

not the only potential delay in the process, however. 

Officers must also observe the subject for 15 to 20 minutes 

to ensure that “residual mouth alcohol,” which can inflate 

results and expose the test to an evidentiary challenge at 

trial, has dissipated and that the subject has not inserted 

any food or drink into his mouth.5 In many States, including Minnesota, officers must then give the motorist a 

window of time within which to contact an attorney before 

administering a test.6 Finally, if a breath test machine is 

—————— 

5See NHTSA and International Assn. of Chiefs of Police, DWI Detection and Standardized Field Sobriety Testing Participant Guide,

Session 7, p. 20 (2013). 6See Minn. Stat. §169A.51, subd. 2(4) (2014) (“[T]he person has the

right to consult with an attorney, but . . . this right is limited to the

extent that it cannot unreasonably delay administration of the test”); 

see also Kuhn v. Commissioner of Public Safety, 488 N. W. 2d 838 

(Minn. App. 1992) (finding 24 minutes insufficient time to contact an 
 

 

Cite as: 579 U. S. ____ (2016) 11 

Opinion of SOTOMAYOR, J. 

not already active, the police officer must set it up. North 

Dakota’s Intoxilyzer 8000 machine can take as long as 30

minutes to “warm-up.”7 

Because of these necessary steps, the standard breath 

test is conducted well after an arrest is effectuated. The 

Minnesota Court of Appeals has explained that nearly all

breath tests “involve a time lag of 45 minutes to two

hours.” State v. Larson, 429 N. W. 2d 674, 676 (Minn. 

App. 1988); see also State v. Chirpich, 392 N. W. 2d 34, 37 

(Minn. App. 1986). Both North Dakota and Minnesota 

give police a 2-hour period from the time the motorist was

pulled over within which to administer a breath test.

N. D. Cent. Code Ann. §39–20–04.1(1) (2008); Minn. Stat.

§169A.20, subd. 1(5) (2014).8 

During this built-in window, police can seek warrants.

That is particularly true in light of “advances” in technology that now permit “the more expeditious processing of 

warrant applications.” McNeely, 569 U. S., at ___–___, and 

n. 4 (slip op., at 11–12, and n. 4) (describing increased

availability of telephonic warrants); Riley, 573 U. S., at 

___ (slip op., at 26) (describing jurisdictions that have

adopted an e-mail warrant system that takes less than 15

minutes); Minn. Rules Crim. Proc. 33.05, 36.01–36.08

(2010 and Supp. 2013) (allowing telephonic warrants); N. 

D. Rules Crim. Proc. 41(c)(2)–(3) (2013) (same). Moreover,
 

counsel for North Dakota explained at oral argument that 

—————— 

attorney before being required to submit to a test).
 7See Office of Attorney General, Crime Lab. Div., Chemical Test

Training Student Manual, Fall 2011–Spring 2012, p. 13 (2011). 8Many tests are conducted at the outer boundaries of that window. 

See, e.g., Israel v. Commissioner of Public Safety, 400 N. W. 2d 428 

(Minn. App. 1987) (57 minute poststop delay); Mosher v. Commissioner 

of Public Safety, 2015 WL 3649344 (Minn. App., June 15, 2015) (119

minute postarrest delay); Johnson v. Commissioner of Public Safety, 

400 N. W. 2d 195 (Minn. App. 1987) (96 minute postarrest delay); 

Scheiterlein v. Commissioner of Public Safety, 2014 WL 3021278 (Minn.

App., July 7, 2014) (111 minute poststop delay). 
 

 

 

12 BIRCHFIELD v. NORTH DAKOTA 

Opinion of SOTOMAYOR, J. 

the State uses a typical “on-call” system in which some

judges are available even during off-duty times.9 See Tr. 

of Oral Arg. 42. 

Where “an officer can . . . secure a warrant while” the 

motorist is being transported and the test is being prepared, this Court has said that “there would be no plausible justification for an exception to the warrant requirement.” McNeely, 569 U. S., at ___ (slip op., at 10). Neither 

the Court nor the States provide any evidence to suggest

that, in the normal course of affairs, obtaining a warrant 

and conducting a breath test will exceed the allotted 2-

hour window. 

Third, the Court and the States cite a governmental

interest in minimizing the costs of gathering evidence of

drunk driving. But neither has demonstrated that requiring police to obtain warrants for breath tests would impose 

a sufficiently significant burden on state resources to

justify the elimination of the Fourth Amendment’s warrant requirement. The Court notes that North Dakota has 

82 judges and magistrate judges who are authorized to 

issue warrants. See ante, at 27-28. Because North Dakota has roughly 7,000 drunk-driving arrests annually, the

Court concludes that if police were required to obtain

warrants “for every search incident to arrest that does not 

involve exigent circumstances, the courts would be 

swamped.” Ante, at 27. That conclusion relies on inflated 

numbers and unsupported inferences.

Assuming that North Dakota police officers do not ob-

—————— 

9Counsel for North Dakota represented at oral argument that in

“larger jurisdictions” it “takes about a half an hour” to obtain a warrant. Tr. of Oral Arg. 42. Counsel said that it is sometimes “harder to 

get somebody on the phone” in rural jurisdictions, but even if it took

twice as long, the process of obtaining a warrant would be unlikely to

take longer than the inherent delays in preparing a motorist for testing 

and would be particularly unlikely to reach beyond the 2-hour window

within which officers can conduct the test. 
Cite as: 579 U. S. ____ (2016) 13 

Opinion of SOTOMAYOR, J. 

tain warrants for any drunk-driving arrests today, and 

assuming that they would need to obtain a warrant for 

every drunk-driving arrest tomorrow, each of the State’s 

82 judges and magistrate judges would need to issue fewer 

than two extra warrants per week.10 Minnesota has nearly

the same ratio of judges to drunk-driving arrests, and so

would face roughly the same burden.11 These back-of-theenvelope numbers suggest that the burden of obtaining a 

warrant before conducting a breath test would be small in

both States. 

But even these numbers overstate the burden by a significant degree. States only need to obtain warrants for 

drivers who refuse testing and a significant majority of 

drivers voluntarily consent to breath tests, even in States 

without criminal penalties for refusal. In North Dakota, 

only 21% of people refuse breath tests and in Minnesota, 

only 12% refuse. NHTSA, E. Namuswe, H. Coleman, & A. 

Berning, Breath Test Refusal Rates in the United States–

2011 Update 2 (No. 811881 2014). Including States that 

impose only civil penalties for refusal, the average refusal

rate is slightly higher at 24%. Id., at 3. Say that North

Dakota’s and Minnesota’s refusal rates rise to double the 

mean, or 48%. Each of their judges and magistrate judges

would need to issue fewer than one extra warrant a 

—————— 

10Seven thousand annual arrests divided by 82 judges and magistrate judges is 85.4 extra warrants per judge and magistrate judge per 

year. And 85.4 divided by 52 weeks is 1.64 extra warrants per judge

and magistrate judge per week. 11Minnesota has about 25,000 drunk-driving incidents each year. 

Minn. Dept. of Public Safety, Office of Traffic Safety, Minn. Impaired 

Driving Facts 2014, p. 2 (2015). In Minnesota, all judges not exercising

probate jurisdiction can issue warrants. Minn. Stat. §626.06 (2009). 

But the state district court judges appear to do the lion’s share of that

work. So, conservatively counting only those judges, the State has 280 

judges that can issue warrants. Minnesota Judicial Branch, Report to 

the Community 23 (2015). Similar to North Dakota, that amounts to 

1.72 extra warrants per judge per week. 
 

 

14 BIRCHFIELD v. NORTH DAKOTA 

Opinion of SOTOMAYOR, J. 

week.12 That bears repeating: The Court finds a categorical exception to the warrant requirement because each of

a State’s judges and magistrate judges would need to issue 

less than one extra warrant a week. 

Fourth, the Court alludes to the need to collect evidence 

conveniently. But mere convenience in investigating 

drunk driving cannot itself justify an exception to the 

warrant requirement. All of this Court’s postarrest exceptions to the warrant requirement require a law enforcement interest separate from criminal investigation. The 

Court’s justification for the search incident to arrest rule

is “the officer’s safety” and the prevention of evidence

“concealment or destruction.” Chimel, 395 U. S., at 763. 

The Court’s justification for the booking exception, which 

allows police to obtain fingerprints and DNA without a

warrant while booking an arrestee at the police station, is 

the administrative need for identification. See Maryland 

v. King, 569 U. S. ___, ___–___ (2013) (slip op., at 11–12). 

The Court’s justification for the inventory search exception, which allows police to inventory the items in the 

arrestee’s personal possession and car, is the need to

“protect an owner’s property while it is in the custody of 

the police, to insure against claims of lost, stolen, or vandalized property, and to guard the police from danger.” 

Colorado v. Bertine, 479 U. S. 367, 372 (1987). 

This Court has never said that mere convenience in 

gathering evidence justifies an exception to the warrant

requirement. See Florida v. Wells, 495 U. S. 1, 4 (1990) 

(suppressing evidence where supposed “inventory” search 

—————— 

12Because each of North Dakota’s judges and magistrate judges 

would have to issue an extra 1.64 warrants per week assuming a 100% 

refusal rate, see supra, at 13, nn. 10–11, they would have to issue an

additional 0.79 per week assuming a 48% refusal rate. Adjusting for

the same conservatively high refusal rate, Minnesota would go from

1.72 additional warrants per judge per week to just 0.82. 
Cite as: 579 U. S. ____ (2016) 15 

Opinion of SOTOMAYOR, J. 

was done without standardized criteria, suggesting instead “‘a purposeful and general means of discovering 

evidence of crime’”). If the simple collection of evidence

justifies an exception to the warrant requirement even

where a warrant could be easily obtained, exceptions 

would become the rule. Ibid. 

Finally, as a general matter, the States have ample tools 

to force compliance with lawfully obtained warrants. This 

Court has never cast doubt on the States’ ability to impose 

criminal penalties for obstructing a search authorized by a 

lawfully obtained warrant. No resort to violent compliance would be necessary to compel a test. If a police officer obtains a warrant to conduct a breath test, citizens 

can be subjected to serious penalties for obstruction of

justice if they decline to cooperate with the test. 

This Court has already taken the weighty step of characterizing breath tests as “searches” for Fourth Amendment purposes. See Skinner, 489 U. S., at 616–617. That 

is because the typical breath test requires the subject to

actively blow alveolar (or “deep lung”) air into the machine. Ibid. Although the process of physically blowing

into the machine can be completed in as little as a few

minutes, the end-to-end process can be significantly longer. 

The person administering the test must calibrate the 

machine, collect at least two separate samples from the

arrestee, change the mouthpiece and reset the machine 

between each, and conduct any additional testing indicated 

by disparities between the two tests.13 Although some

searches are certainly more invasive than breath tests, 

this Court cannot do justice to their status as Fourth

Amendment “searches” if exaggerated time pressures,

mere convenience in collecting evidence, and the “burden” 

—————— 

13See Office of Attorney General, Crime Lab. Div., Approved Method 

To Conduct Breath Tests With the Intoxilyzer 8000 (BRS–001), pp. 4–6,

8 (2012). 
 

 

16 BIRCHFIELD v. NORTH DAKOTA 

Opinion of SOTOMAYOR, J. 

of asking judges to issue an extra couple of warrants per 

month are costs so high as to render reasonable a search

without a warrant.14 The Fourth Amendment becomes an 

empty promise of protecting citizens from unreasonable 

searches. 

B 

After evaluating the governmental and privacy interests

at stake here, the final step is to determine whether any

situations in which warrants would interfere with the 

States’ legitimate governmental interests should be accommodated through a case-by-case or categorical exception to the warrant requirement. 

As shown, because there are so many circumstances in 

which obtaining a warrant will not delay the administration of a breath test or otherwise compromise any governmental interest cited by the States, it should be clear that

allowing a categorical exception to the warrant requirement is a “considerable overgeneralization” here. 

McNeely, 569 U. S., at ___ (slip op., at 10). As this Court 

concluded in Riley and McNeely, any unusual issues that 

—————— 

14 In weighing the governmental interests at stake here, the Court 

also downplays the “benefits” that warrants provide for breath tests. 

Because this Court has said unequivocally that warrants are the usual 

safeguard against unreasonable searches, see Katz v. United States, 

389 U. S. 347, 357 (1967), the legal relevance of this discussion is not

clear. In any event, the Court is wrong to conclude that warrants 

provide little benefit here. The Court says that any warrants for breath

tests would be issued based on the “characterization” of the police 

officer, which a “magistrate would be in a poor position to challenge.” 

Ante, at 29. Virtually all warrants will rely to some degree on an 

officer’s own perception. The very purpose of warrants is to have a 

neutral arbiter determine whether inferences drawn from officers’ 

perceptions and circumstantial evidence are sufficient to justify a 

search. Regardless of the particulars, the Court’s mode of analysis is a

dangerous road to venture down. Historically, our default has been 

that warrants are required. This part of the Court’s argument instead

suggests, without precedent, that their value now has to be proven. 
Cite as: 579 U. S. ____ (2016) 17 

Opinion of SOTOMAYOR, J. 

do arise can “better [be] addressed through consideration of case-specific exceptions to the warrant requirement.” Riley, 573 U. S., at ___ (slip op., at 11); see also 

McNeely, 569 U. S., at ___ (slip op., at 15) (opinion of 

SOTOMAYOR, J.). 

Without even considering the comparative effectiveness 

of case-by-case and categorical exceptions, the Court

reaches for the categorical search-incident-to-arrest exception and enshrines it for all breath tests. The majority

apparently assumes that any postarrest search should be 

analyzed under the search-incident-to-arrest doctrine. See 

ante, at 16 (“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”).

But, as we explained earlier, police officers may want to

conduct a range of different searches after placing a person under arrest. Each of those searches must be separately analyzed for Fourth Amendment compliance. Two 

narrow types of postarrest searches are analyzed together 

under the rubric of our search-incident-to-arrest doctrine: 

Searches to disarm arrestees who could pose a danger

before a warrant is obtained and searches to find evidence 

arrestees have an incentive to destroy before a warrant is

obtained. Chimel, 395 U. S., at 763. Other forms of 

postarrest searches are analyzed differently because they

present needs that require more tailored exceptions to the 

warrant requirement. See supra, at 4–5 (discussing

postarrest application of the “exigency” exception); see also 

supra, at 13–14 (discussing postarrest booking and inventory exceptions). 

The fact that a person is under arrest does not tell us

which of these warrant exceptions should apply to a particular kind of postarrest search. The way to analyze 
 

 

 

18 BIRCHFIELD v. NORTH DAKOTA 

Opinion of SOTOMAYOR, J. 

which exception, if any, is appropriate is to ask whether 

the exception best addresses the nature of the postarrest 

search and the needs it fulfills. Yet the majority never

explains why the search-incident-to-arrest framework—its 

justifications, applications, and categorical scope—is best

suited to breath tests. 

To the contrary, the search-incident-to-arrest exception

is particularly ill suited to breath tests. To the extent the 

Court discusses any fit between breath tests and the

rationales underlying the search-incident-to-arrest exception, it says that evidence preservation is one of the core

values served by the exception and worries that “evidence 

may be lost” if breath tests are not conducted. Ante, at 31. 

But, of course, the search-incident-to-arrest exception is 

concerned with evidence destruction only insofar as that

destruction would occur before a warrant could be sought.

And breath tests are not, except in rare circumstances,

conducted at the time of arrest, before a warrant can be 

obtained, but at a separate location 40 to 120 minutes 

after an arrest is effectuated. That alone should be reason 

to reject an exception forged to address the immediate 

needs of arrests. 

The exception’s categorical reach makes it even less

suitable here. The search-incident-to-arrest exception is

applied categorically precisely because the needs it addresses could arise in every arrest. Robinson, 414 U. S., at 

236. But the government’s need to conduct a breath test is

present only in arrests for drunk driving. And the asserted 

need to conduct a breath test without a warrant arises 

only when a warrant cannot be obtained during the significant built-in delay between arrest and testing. The conditions that require warrantless breath searches, in short,

are highly situational and defy the logical underpinnings 

of the search-incident-to-arrest exception and its categorical application. 
 

Cite as: 579 U. S. ____ (2016) 19 

Opinion of SOTOMAYOR, J. 

* * * 

In Maryland v. King, this Court dispensed with the

warrant requirement and allowed DNA searches following 

an arrest. But there, it at least attempted to justify the

search using the booking exception’s interest in identifying 

arrestees. 569 U. S., at ___–___ (slip op., at 11–18); id., at 

___–___ (slip op., at 4–6) (Scalia, J., dissenting). Here, the 

Court lacks even the pretense of attempting to situate 

breath searches within the narrow and weighty law enforcement needs that have historically justified the limited 

use of warrantless searches. I fear that if the Court continues down this road, the Fourth Amendment’s warrant 

requirement will become nothing more than a suggestion. 
THOMAS, J., concurring in part and dissenting in part 

_________________ 

_________________ 

Cite as: 579 U. S. ____ (2016) 1 

Opinion of THOMAS, J. 

SUPREME COURT OF THE UNITED STATES 

Nos. 14–1468, 14–1470, and 14–1507 

DANNY BIRCHFIELD, PETITIONER 

14–1468 v. 

NORTH DAKOTA; 

ON WRIT OF CERTIORARI TO THE SUPREME COURT OF
 

NORTH DAKOTA
 

WILLIAM ROBERT BERNARD, JR., PETITIONER 

14–1470 v. 

MINNESOTA; AND 

ON WRIT OF CERTIORARI TO THE SUPREME COURT OF
 

MINNESOTA
 

STEVE MICHAEL BEYLUND, PETITIONER 

14–1507 v. 

GRANT LEVI, DIRECTOR, NORTH DAKOTA 

DEPARTMENT OF TRANSPORTATION 

ON WRIT OF CERTIORARI TO THE SUPREME COURT OF
 

NORTH DAKOTA
 

[June 23, 2016] 

JUSTICE THOMAS, concurring in judgment in part and 

dissenting in part. 

The compromise the Court reaches today is not a good 

one. By deciding that some (but not all) warrantless tests

revealing the blood alcohol concentration (BAC) of an

arrested driver are constitutional, the Court contorts the 

search-incident-to-arrest exception to the Fourth Amendment’s warrant requirement. The far simpler answer to 
 

THOMAS, J., concurring in part and dissenting in part 

2 BIRCHFIELD v. NORTH DAKOTA 

Opinion of THOMAS, J. 

the question presented is the one rejected in Missouri v. 

McNeely, 569 U. S. ___ (2013). Here, the tests revealing 

the BAC of a driver suspected of driving drunk are constitutional under the exigent-circumstances exception to the

warrant requirement. Id., at ___–___ (THOMAS, J., dissenting) (slip op., at 3–4). 

I 

Today’s decision chips away at a well-established exception to the warrant requirement. Until recently, we have

admonished that “[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.” United States v. Robinson, 414 U. S. 218, 235 

(1973). Under our precedents, a search incident to lawful 

arrest “require[d] no additional justification.” Ibid. Not 

until the recent decision in Riley v. California, 573 U. S. 

___ (2014), did the Court begin to retreat from this categorical approach because it feared that the search at issue, 

the “search of the information on a cell phone,” bore “little 

resemblance to the type of brief physical search” contemplated by this Court’s past search-incident-to-arrest decisions. Id., at ___ (slip op., at 10). I joined Riley, however, 

because the Court resisted the temptation to permit 

searches of some kinds of cell-phone data and not others, 

id., at ___–___ (slip op., at 23–25), and instead asked more 

generally whether that entire “category of effects” was

searchable without a warrant, id., at ___ (slip op., at 10). 

Today’s decision begins where Riley left off. The Court 

purports to apply Robinson but further departs from its

categorical approach by holding that warrantless breath

tests to prevent the destruction of BAC evidence are constitutional searches incident to arrest, but warrantless 

blood tests are not. Ante, at 35 (“Because breath tests are 
THOMAS, J., concurring in part and dissenting in part 

 

 

Cite as: 579 U. S. ____ (2016) 3 

Opinion of THOMAS, J. 

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”). That hairsplitting makes little sense. Either 

the search-incident-to-arrest exception permits bodily 

searches to prevent the destruction of BAC evidence, or it

does not. 

The Court justifies its result—an arbitrary line in the 

sand between blood and breath tests—by balancing the 

invasiveness of the particular type of search against the

government’s reasons for the search. Ante, at 20–36. 

Such case-by-case balancing is bad for the People, who 

“through ratification, have already weighed the policy

tradeoffs that constitutional rights entail.” Luis v. United 

States, 578 U. S. ___, ___ (2016) (THOMAS, J., concurring in 

judgment) (slip op., at 10); see also Crawford v. Washington, 541 U. S. 36, 67–68 (2004). It is also bad for law 

enforcement officers, who depend on predictable rules to

do their job, as Members of this Court have exhorted in

the past. See Arizona v. Gant, 556 U. S. 332, 359 (2009) 

(ALITO, J., dissenting); see also id., at 363 (faulting the 

Court for “leav[ing] the law relating to searches incident to

arrest in a confused and unstable state”).

Today’s application of the search-incident-to-arrest 

exception is bound to cause confusion in the lower courts. 

The Court’s choice to allow some (but not all) BAC searches

is undeniably appealing, for it both reins in the pernicious problem of drunk driving and also purports to preserve some Fourth Amendment protections. But that 

compromise has little support under this Court’s existing

precedents. 

II 

The better (and far simpler) way to resolve these cases 

is by applying the per se rule that I proposed in McNeely. 
 

THOMAS, J., concurring in part and dissenting in part 

4 BIRCHFIELD v. NORTH DAKOTA 

Opinion of THOMAS, J. 

Under that approach, both warrantless breath and blood 

tests are constitutional because “the natural metabolization of [BAC] creates an exigency once police have probable cause to believe the driver is drunk. It naturally follows that police may conduct a search in these 

circumstances.” 569 U. S., at ___–___ (dissenting opinion) 

(slip op., at 3–4).

The Court in McNeely rejected that bright-line rule and

instead adopted a totality-of-the-circumstances test examining whether the facts of a particular case presented 

exigent circumstances justifying a warrantless search. 

Id., at ___ (slip op., at 1). The Court ruled that “the natural dissipation of alcohol in the blood” could not “categorically” create an “exigency” in every case. Id., at ___ (slip 

op., at 13). The destruction of “BAC evidence from a 

drunk-driving suspect” that “naturally dissipates over 

time in a gradual and relatively predictable manner,” 

according to the Court, was qualitatively different from

the destruction of evidence in “circumstances in which the 

suspect has control over easily disposable evidence.” Id., 

at ___ (slip op., at 10). 

Today’s decision rejects McNeely’s arbitrary distinction

between the destruction of evidence generally and the

destruction of BAC evidence. But only for searches incident to arrest. Ante, at 31–33. The Court declares that 

such a distinction “between an arrestee’s active destruction of evidence and the loss of evidence due to a natural 

process makes little sense.” Ante, at 31. I agree. See 

McNeely, supra, at ___–___ (THOMAS, J., dissenting) (slip

op., at 5–6). But it also “makes little sense” for the Court 

to reject McNeely’s arbitrary distinction only for searches 

incident to arrest and not also for exigent-circumstances

searches when both are justified by identical concerns

about the destruction of the same evidence. McNeely’s 

distinction is no less arbitrary for searches justified by

exigent circumstances than those justified by search inci- 
THOMAS, J., concurring in part and dissenting in part 

 

Cite as: 579 U. S. ____ (2016) 5 

Opinion of THOMAS, J. 

dent to arrest. 

The Court was wrong in McNeely, and today’s compromise is perhaps an inevitable consequence of that error.

Both searches contemplated by the state laws at issue in

these cases would be constitutional under the exigentcircumstances exception to the warrant requirement. I 

respectfully concur in the judgment in part and dissent in 

part.