U.S. Supreme Court: Warrant needed for blood test in DWI cases

In the recent case, Missouri v. McNeely, the U.S. Supreme Court ruled that police officers must obtain a warrant before subjecting a suspected drunk driver to a blood test.  Justice Clarence Thomas was the only justice to oppose the decision, making the final vote eight to one.

This particular case made it to the Supreme Court after a man named Tyler McNeely was pulled over by a state trooper in Missouri because he was driving erratically. McNeely refused to take the requested breathalyzer test on the side of the road. Consequently, the trooper drove the man to a hospital and forced him to have his blood drawn for an alcohol test. Even though the trooper had acquired a warrant in previous cases like this one, he did not do so this time. When the case went to court, the state decided that a warrant should not be required to draw a suspected drunk driver’s blood because alcohol dissipates in the bloodstream naturally and that waiting for a warrant means valuable evidence would be lost. 

The Supreme Court’s decision 

The Supreme Court disagreed with the state of Missouri on the basis that in most drunk driving cases, there is adequate time for a police officer to obtain a warrant. Justice Sonya Sotomayor, on behalf of the rest of the Supreme Court justices, noted that thanks to today’s advancements in technology, a law enforcement official can obtain a warrant quickly and easily using email or their cellphone. Additionally, a magistrate is available at all hours in the majority of jurisdictions to grant warrant requests.

Although this case does require police officers to obtain a warrant before performing a blood test on a suspected drunk driver, it also recognizes that there are emergency situations where a warrant may not be the best course of action. If a police officer can prove that there are “exigent circumstances,” aside from the alcohol metabolizing within the bloodstream, they may take a blood test without a warrant. 

Minnesota DWI laws 

While this ruling mandates that police officers must have a warrant before taking a blood test, Minnesota’s implied consent law still requires suspected drunk drivers to take a blood, breath or urine test if arrested for a DWI for the purpose of determining the blood alcohol content level of the driver.  The officer at the scene of the arrest:

  • Gets to choose which test is taken
  • Has to administer the test within two hours following the arrest
  • May require an additional test if it is suspected that drugs and alcohol are both involved 

Those arrested on DWI charges may benefit from working with an attorney who can mitigate the consequences of this legal allegation.

Max Keller has won countless jury trial cases involving misdemeanors and felonies, sex crimes, and DWI’s. He is a member of the Minnesota Society for Criminal Justice, which only allows the top 50 criminal defense attorneys in the state as members. Max is a frequent speaker at CLE’s and is often asked for advice by other defense attorneys across Minnesota.

Experience: Practicing since 1997
Minnesota Registration Status: Active
Bar & Court Admissions: State of Minnesota Minnesota State Court Minnesota Federal Court 8th Circuit Federal Court of Appeals State of Maryland

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