Play Live Radio
Next Up:
0:00 0:00
Available On Air Stations

Can Police Force Drunken Driving Suspects To Take Blood Tests?

A photographic screen hangs in front of the U.S. Supreme Court, which is undergoing renovations. On Wednesday, the justices will hear arguments in a case that asks whether police without a warrant can administer a blood test to a suspected drunken driver.
Greg E. Mathieson
A photographic screen hangs in front of the U.S. Supreme Court, which is undergoing renovations. On Wednesday, the justices will hear arguments in a case that asks whether police without a warrant can administer a blood test to a suspected drunken driver.

The U.S. Supreme Court hears arguments Wednesday in a case testing whether police must get a warrant before forcing a drunken driving suspect to have his blood drawn.

The court has long held that search warrants are ordinarily required when government officials order intrusions into the body — intrusions like drawing blood from an unwilling individual. The court has reasoned that such intrusions amount to a bodily search and thus are covered by the Fourth Amendment's warrant requirement. But the court has also ruled that there are exceptions to that requirement in what are called exigent situations — emergencies. And Wednesday's case tests how broad the definition of an emergency may be.

The case began in Missouri in 2010. Tyler McNeely was driving 56 mph in a 45 mph zone at 2 a.m., when he was stopped by state highway Patrolman Mark Winder. The officer administered four field sobriety tests. McNeely failed all of them, and when he refused to submit to a Breathalyzer test, he was arrested and taken to a hospital, where he also refused to allow his blood to be drawn. Although Winder had gotten warrants in the past without difficulty in such situations, he did not try to get one this time. He ordered the blood drawn. It showed a blood alcohol level well above the legal limit, and McNeely was charged with driving under the influence.

At trial, though, the judge threw out the blood test because it was obtained without a warrant. The Missouri state Supreme Court unanimously agreed, noting that there were no events that would have interfered with getting a warrant — there was no accident to investigate, no injury requiring medical attention, and a judge was on call to review a warrant application quickly. The state court said that under these circumstances, there was no justification for failing to get a warrant before forcing an unwilling suspect to have his blood drawn.

The state of Missouri appealed, contending that because alcohol dissipates in the bloodstream over time, that alone constitutes an emergency situation that justifies forcing a blood draw without a warrant.

"Our main point is that under the exigent circumstances exception, when we know for certain that important, reliable, evidence is in the process of being destroyed, a search warrant is not necessary because, during any delay to obtain a search warrant, you are allowing the best evidence of the crime to dissipate and be destroyed," says John Koester, assistant prosecuting attorney for Cape Girardeau, Mo. The state also maintains that in these circumstances, a warrantless blood draw is "a minimal intrusion."

But Steven Shapiro of the American Civil Liberties Union, representing McNeely, counters that alcohol dissipates over a matter of hours, and that here, where there was no emergency that could have interfered, a warrant could have been quickly obtained.

The arresting officer testified that he had never had problems getting warrants in the past. In fact, he testified that the only reason he didn't get a warrant was that he had seen an opinion from the state prosecutor's office saying that they were unnecessary in routine cases. That contradicted an opinion from the county attorney's office and a state police legal advisory.

The ACLU's Shapiro explains the reason for the warrant this way: "For the police to order medical professionals to put a needle into your arm and take blood is a fairly significant ... intrusion on your privacy and your bodily integrity. And that ought not to be a decision that the police are making without review by a judge."

Indeed, he observes, warrants can and were obtained in other cases in a half-hour or less, and a majority of states do require such warrants. He also notes that McNeely's refusal to agree to the blood test can have adverse consequences for the accused, since the refusal can be used as evidence against him at trial.

The Obama administration, however, backs up Missouri in its contention that the need for quick blood-alcohol testing outweighs any individual privacy interest. Time, the government argues, is of the essence, since a person's blood alcohol starts to dissipate after he or she stops drinking.

The government notes that in 2010, more than 10,000 people were killed in motor-vehicle accidents that involved alcohol-impaired drivers. That is one death every 51 minutes.

Copyright 2021 NPR. To see more, visit

Nina Totenberg is NPR's award-winning legal affairs correspondent. Her reports air regularly on NPR's critically acclaimed newsmagazines All Things Considered, Morning Edition, and Weekend Edition.