Supreme Court Clarifies Rules for Breath and Blood Tests in DUI Cases
June 29, 2016
The law surrounding DUI investigations continues to evolve. In a significant decision, the United States Supreme Court addressed whether police must obtain a warrant before requiring breath or blood tests from drivers arrested for DUI. The case, Birchfield v. North Dakota (DUI Law), helped clarify what officers can — and cannot — do following a DUI arrest.
The Court reviewed three separate cases involving drivers who either refused testing or consented after being told refusal could be a crime. Each case raised questions about whether warrantless breath or blood tests violated the Fourth Amendment.
Breath Tests vs. Blood Tests
In its decision, the Court drew an important distinction between breath tests and blood tests.
The justices determined that breath tests are minimally intrusive and do not raise the same privacy concerns as blood draws. Because of this, officers may generally administer a breath test after a lawful DUI arrest without first obtaining a warrant.
Blood tests, however, are more invasive because they require piercing the skin and collecting a sample that can reveal more personal information. For that reason, the Court held that police usually must obtain a warrant before conducting a blood draw.
Refusing a Test
The ruling also addressed what happens when a driver refuses testing.
The Court concluded that:
States may make it a crime to refuse a breath test after a lawful DUI arrest.
States may not criminally penalize a driver for refusing a warrantless blood draw.
Civil penalties — such as license suspension — may still apply for refusing either type of test, depending on state law.
Important Exceptions
While blood tests generally require a warrant, there are limited situations where officers may still proceed without one. For example, courts have recognized exceptions when exigent circumstances exist, such as medical emergencies or situations where obtaining a warrant would significantly delay the investigation. These situations are evaluated on a case-by-case basis.
DUI laws continue to become more complex, and each case presents unique circumstances. If nothing else, this ruling serves as a reminder of the serious legal consequences that can follow a DUI arrest — and why making informed decisions is so important.
What This Means for Drivers
The takeaway from this decision is that breath and blood tests are treated differently under the law. After a DUI arrest, officers will often request a breath test, and refusal may carry criminal consequences in some jurisdictions. Blood tests, on the other hand, typically require a warrant unless special circumstances apply.
Because DUI laws and procedures can vary by state and continue to develop through court decisions, it is important to understand your rights and obligations if you are facing a DUI investigation. Contact our Seattle criminal defense attorney today to discuss the specifics of your case and enlist experienced representation.