Birchfield v. N. Dakota. William Robert Bernard
The Supreme Court ruled that police may require a breath test from a drunk-driving arrestee without a warrant, but they generally may not require a blood test without one.
Because states cannot force blood tests without a warrant, the Court also held that a driver cannot be criminally punished simply for refusing a blood test, even under a state's implied-consent law. Breath test refusals, however, can still be criminalized.
How it got here: State courts in North Dakota and Minnesota upheld criminal penalties and license suspensions tied to alcohol-test refusal or coerced consent; the drivers asked the Supreme Court to review all three rulings together.
The Case in Depth
What happened
Three men were arrested on drunk-driving charges in North Dakota and Minnesota. Two refused testing after being warned that refusal itself was a crime under their state's law, and one agreed to a blood draw after receiving the same warning. All three later challenged whether the Constitution allowed states to criminally punish or coerce them into submitting to alcohol testing without a warrant.
The question before the Court
If you're arrested for drunk driving, can police test your breath or blood for alcohol without first getting a warrant?
Why it matters
Millions of people are arrested for drunk driving every year, and this ruling sets the rules police must follow. Breath tests can still be demanded on the spot and refusal can be a crime, but drivers cannot be criminally punished for declining a blood draw unless police first get a warrant or face a true emergency.
What changes now
This is a final merits ruling, not a temporary order. Birchfield's blood-test refusal conviction was reversed and sent back for further proceedings; Bernard's breath-test refusal conviction was affirmed because breath tests can be demanded without a warrant; and Beylund's case was sent back so North Dakota's courts can reassess whether his consent to a blood test was truly voluntary given the partly incorrect warning he received.
What this does not decide
The Court did not disturb ordinary implied-consent laws that impose civil penalties, like license suspension, for refusing testing. It also left open whether police can still get warrants or rely on true emergencies to justify warrantless blood draws in unusual situations, such as when a driver is unconscious.
Concurrences and dissents
Dissent in part — Justice Sotomayor
Sotomayor agreed that warrantless blood tests are unconstitutional but disagreed that warrantless breath tests should be allowed under the search-incident-to-arrest exception. She argued police usually have a built-in window of 45 minutes to two hours before testing, plenty of time to get a warrant, especially given modern telephonic warrant systems, so a categorical exception is unnecessary.
Dissent in part — Justice Thomas
Thomas argued the Court's breath-versus-blood distinction is an arbitrary line that makes little sense once the majority accepts that natural alcohol metabolism justifies bypassing the warrant requirement. He would instead hold both breath and blood tests constitutional without a warrant, reviving the bright-line exigency rule he proposed and lost in an earlier case, McNeely.
How the Court got there
The legal reasoning, step by step
- The Court applied the search-incident-to-arrest doctrine, which lets police search an arrested person without a warrant, and asked whether it should extend categorically to breath and blood alcohol tests, since the founding era gave no clear answer for this modern situation.
- Following the approach used in a recent cell-phone search case, the Court weighed how much a test intrudes on personal privacy against how much the government needs it, rather than deciding case-by-case whether a warrant could have been obtained in time.
- Breath tests were found only mildly intrusive: no piercing of skin, quick, and leaving no biological sample in police hands, making them comparable to a cheek swab already allowed without a warrant.
- Blood tests were found significantly more intrusive because they pierce the skin and create a lasting biological sample that could later reveal much more than a blood alcohol reading.
- Weighing these privacy costs against the government's strong interest in deterring drunk driving and obtaining reliable evidence, the Court concluded breath tests could be required without a warrant as part of an arrest, but blood tests generally could not.
- Because blood tests require a warrant absent an emergency, the Court held that motorists cannot be deemed to have automatically agreed, just by driving on public roads, to face criminal punishment for refusing one.
Doctrinal impact
Cases affected by this decision
Distinguishes Missouri v. McNeely (569 U. S. ___)
The Court said McNeely's case-by-case exigency test does not govern the separate, categorical search-incident-to-arrest exception at issue here.
Limits Chimel v. California (395 U. S. 752)
The Court read Chimel's evidence-destruction rationale to also cover natural loss of evidence, not just an arrestee's deliberate destruction.