As a result of the Supreme Court’s decision in Birchfield v. North Dakota in states that criminalize the refusal to take a blood alcohol concentration tests, officers should offer only a breath (not blood) test unless they have a warrant.

The Court held 5-3 that states may criminalize an arrestee’s refusal to take a warrantless breath test. If states criminalize the refusal to take a blood test police must obtain a warrant. The State and Local Legal Center (SLLC) filed an amicus brief arguing that states should be able to criminalize warrantless refusal to consent when a person is arrested upon suspicion of drunken driving.  

The National Conference of State Legislatures reports that 15 states currently criminalize refusal to consent. Criminal penalties typically include fines and jail time.    

As the Court points out, states began criminalizing the refusal to consent to blood alcohol concentration (BAC) testing because the penalty for refusal is low—typically driver’s license revocation or suspension. National Highway Traffic Safety Administration research indicates about 20 percent of people arrested for drunken driving refuse to submit to a BAC test.

The Supreme Court has generally interpreted the Fourth Amendment’s prohibition against unreasonable searches to require police to obtain a warrant before conducting a search. However, the Court has created numerous exceptions to the warrant requirement. The exception relevant in this case, according to Justice Alito writing for the majority of the Court, was search-incident-to-arrest. A motorist is only required to submit to a BAC test after being arrested for drunken driving.

Per the search-incident-to-arrest exception, police officers are allowed to search an arrestee’s person, without first obtaining a warrant, to protect officer safety or evidence. To determine if this exception applies the Court weighed the degree to which the search “intrudes upon an individual’s privacy” with the need to promote “legitimate government interests.”

The Court concluded the privacy intrusion of breath tests was minimal but the privacy intrusion of blood tests was not. “[W]hile humans exhale air from their lungs many times per minute, humans do not continually shed blood.” For this reason the Court concluded if states criminalize the refusal to take a blood test police must obtain a warrant. The Court noted that blood tests have some advantages (they can detect drugs, and not just alcohol, and they require less driver participation) but breath tests are equally effective.

The Court was also sympathetic to the argument that getting a warrant to compel a BAC test in every drunken driving arrest isn’t realistic. North Dakota’s population is about 740,000 and nearly 7,000 people a year are arrested for drunken driving.

Greg Garre, Jonathan Ellis, and Ben Snyder of Latham Watkins, wrote the SLLC which was joined by the Council of State Governments, National Association of Counties, National League of Cities, United States Conference of Mayors, International City/County Management Association, and the International Municipal Lawyers Association.