## Facts

- Three consolidated matters challenged state “implied-consent” and refusal statutes tied to chemical testing after drunk-driving arrests in North Dakota and Minnesota.
- Danny Birchfield was prosecuted in North Dakota for refusing a warrantless blood test after a DUI arrest.
- William Bernard, Jr. was prosecuted in Minnesota for refusing a warrantless breath test after a DUI arrest.
- Steve Beylund submitted to a blood test after being warned that refusal was a crime; North Dakota later revoked his license in an administrative proceeding based on the blood-test results.
- The North Dakota and Minnesota supreme courts upheld (1) criminal penalties for refusal and (2) the use of the obtained test results in the administrative setting, rejecting Fourth Amendment challenges.
- The U.S. Supreme Court reviewed whether the Fourth Amendment allows states to criminalize refusal to submit to warrantless chemical testing for blood-alcohol evidence.

## Issues

1. Whether warrantless breath or blood tests may be conducted as searches incident to a lawful drunk-driving arrest.
2. Whether a state may criminally punish refusal to submit to a warrantless breath test.
3. Whether a state may criminally punish refusal to submit to a warrantless blood test.
4. Whether purported consent to a blood test is voluntary when given after a warning that refusal is itself a crime.

## Decision

- The Court held that warrantless breath tests are permissible searches incident to arrests for drunk driving.
- The Court held that warrantless blood tests are not categorically permissible as searches incident to drunk-driving arrests.
- The Court held that states may impose criminal penalties for refusing a breath test demanded incident to a lawful DUI arrest.
- The Court held that motorists who refuse a blood test may be subject to civil penalties (such as license consequences) but not criminal penalties for refusal in the ordinary case.
- As applied:
  - Bernard’s conviction for refusing a breath test was upheld.
  - Birchfield’s conviction for refusing a blood test was vacated.
  - Beylund’s case was remanded to determine whether his consent to a blood draw was voluntary given the threat of an unconstitutional refusal crime.

## Legal Principles

- Breath and blood tests are Fourth Amendment “searches,” but they differ in the degree of intrusion and the privacy interests implicated.
- Under the search-incident-to-arrest exception, a warrantless breath test following a lawful drunk-driving arrest is categorically reasonable due to minimal physical intrusion, limited information revealed, and strong governmental interests in enforcing BAC laws.
- A warrantless blood draw is materially more intrusive and yields a retained biological sample; it is not justified categorically as a search incident to a drunk-driving arrest.
- When a warrantless search demand is constitutionally valid (breath test incident to arrest), a state may criminalize refusal to comply with that demand.
- When a warrantless search demand is not constitutionally justified (blood test absent a warrant or another exception), criminalizing refusal impermissibly penalizes assertion of Fourth Amendment rights; states are limited to civil consequences for refusal.
- Blood testing remains available through warrants or case-specific exceptions (including exigent circumstances where applicable).

## Conclusion

The Court drew a constitutional line between breath and blood testing after DUI arrests: breath tests may be required without a warrant as searches incident to arrest and refusal may be punished criminally, while blood tests generally require a warrant or a separate exception and refusal may not be made a crime, with consent obtained under an invalid refusal threat requiring scrutiny for voluntariness.


Birchfield v. North Dakota, 579 U.S. 438 (2016)