The US Supreme Court [official website] ruled [opinion, PDF] 7-1 Thursday in Birchfield v. North Dakota [SCOTUSblog materials] that governments can require suspected drunk drivers to undergo breath tests without first obtaining a warrant, but cannot require them to take a more invasive blood test. The case came to the Supreme Court through three unrelated cases in Minnesota and North Dakota. In the Minnesota case, William Bernard was charged with refusing a blood alcohol concentration (BAC) breath test. However, his charges were dismissed by the state’s district court, which concluded that the warrantless breath test was not permitted under the Fourth Amendment. That ruling was affirmed by the Minnesota Supreme Court. In the North Dakota case, Danny Birchfield and Steve Beylund were arrested and charged for refusing to submit to a BAC blood test. Their charges were upheld by that state’s district courts, which rejected both Birchfield’s argument that the Fourth Amendment prohibited criminalizing his refusal to submit to a blood test and Beylund’s argument that his consent to a blood test was coerced by an officer’s warning. These rulings were affirmed by the North Dakota Supreme Court. The US Supreme Court reversed the rulings of both the states’ highest courts in an opinion by Justice Samuel Alito:

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. … 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. … Bernard, on the other hand, was criminally prosecuted for refusing a warrantless breath test. That test was a permissible search incident to Bernard’s arrest for drunk driving. The Fourth Amendment did not re­quire officers to obtain a warrant prior to demanding the test, and Bernard had no right to refuse it.

The court remanded Beylund’s case to the state court to reevaluate consent given the partial inaccuracy of the officer’s ruling—i.e. the erroneous advice that the state could permissibly compel both blood and breath BAC tests. Justice Sonia Sotomayor wrote a concurring opinion, while Justice Clarence Thomas concurred in part in the judgment and dissented in part.

This opinion is part of a series of decisions being decided by the Supreme Court as it nears the last day of its current term. Many other groundbreaking decisions have been released by the Supreme Court in the last week including another Fourth Amendment case, Utah v. Strieff, that included a scathing dissent from Sotomayor and a decision on a race-conscious college admissions program [JURIST reports] at the University of Texas. More opinions are expected to be released on Monday.