Should cops be forced to get a warrant before giving a blood test to a drunk driver?

Officer Kevin Millan, from the City of Miami Beach police department, conducts a field sobriety test at a DUI traffic checkpoint.
Does the Constitution ever requires the police to get a warrant to test the blood of a suspected drunk driver after his arrest?

Photgrapho by Joe Raedle/Getty Images.

At 2:08 a.m. on Oct. 3, 2010, Missouri highway patrol officer Mark Winder pulled over Tyler McNeely for driving 11 miles over the speed limit. Winder noticed that McNeely’s eyes were bloodshot and that he was slurring his speech, and smelled alcohol on his breath. Winder asked him to get out of his car and do a field-sobriety test—as in, walk a straight line. McNeely did badly. Winder arrested him for drunk driving and asked him to take a breathalyzer. McNeely said no.  

The next step was a blood test, which Winder drove McNeely to the hospital for. In past cases, Winder testified, he’d called in for a warrant before conducting a blood test on a drunk-driving suspect. That’s because the Fourth Amendment requires the police to get a warrant from a judge before conducting most searches. But this time, Winder didn’t try to get a warrant—not because he thought there was an emergency, or even because he worried that he didn’t have time before McNeely’s blood alcohol level dissipated. Instead, Winder didn’t get the warrant because he’d recently read an article by a prosecutor that said police in Missouri no longer needed warrants before forcing a blood test on a drunk-driving suspect.

McNeely got a blood test at 2:33 a.m., despite his objections. His blood alcohol level tested at 0.154 percent, above the legal limit of .08 percent, and he was charged with drunk driving. He filed a motion to keep the blood test out of court because it was done without his consent and without a warrant. His challenge went up to the Missouri Supreme Court, which found that the testing was unconstitutional. Winder was wrong, the court said: Police in Missouri normally must get a warrant before testing the blood of drivers like McNeely.

On Wednesday, the Supreme Court will hear arguments in McNeely’s case, in an appeal brought by the state of Missouri. The question will be whether the Constitution ever requires the police to get a warrant to test the blood of a suspected drunk driver after his arrest.

The Supreme Court ruled more than 40 years ago that the police can forgo warrants when they have reason to think that if they don’t act fast, the evidence will swim out of their suspect’s bloodstream. In the 1966 case Schmerber v. California, the driver with the bloodshot eyes and the alcohol on his breath skidded off the road and was taken to the hospital for treatment. He was arrested there, and after ordering his blood drawn, the police argued in court that they hadn’t had time to get a warrant, given the time it took to bring the defendant to the hospital and investigate the scene of the accident. The Supreme Court, in an opinion by Justice William Brennan, called these “special facts” and said that only in light of them was the warrantless test OK.

The states have since split over how to interpret Schmerber. Utah and Iowa, for example, say the police need to show some kind of urgency (in legalese, an “exigent circumstance”) to test the blood of a suspected drunk driver without a warrant. Wisconsin, Oregon, and Minnesota, on the other hand, say that the dissipation of blood alcohol creates enough exigency on its own—and so warrants are never required. Meanwhile, about one-half the states have passed laws barring warrantless blood tests, either entirely or unless a drunk-driving case involves death or serious bodily injury.

My first instinct was that the states are split because this is a close question. On the one hand, the dangers of drunk driving make a warrant requirement seem like more trouble than the drivers deserve. As Mothers Against Drunk Driving points out, drunk driving causes up to 10,000 deaths and leads to 1.4 million arrests a year. (That’s down from 25,000 annual fatalities two decades ago, but still.) And it’s true that blood alcohol level dissipates over time, at an unpredictable rate. So defense lawyers do try to use testing delays to persuade judges and juries to give little weight to the results, according to a Massachusetts study that MADD cites.

On the other hand, being forced to go to the hospital to take a blood test isn’t necessarily a small thing. New York University law professor Erin Murphy convinced me of this with the following scenario: Imagine that you’ve had a beer, and you’re on your way to your daughter’s graduation. You get pulled over for speeding, and for whatever reason, you irritate the cop who stopped you. He says he smells alcohol on your breath. He tells you to get out and walk a straight line—and then says you didn’t walk it straight, even though you think you did. “The cop decides to make your life miserable by taking you to the hospital—and too bad if you miss the graduation,” Murphy said. “He has the power. And his power is only checked if he has to ask permission.”

Maybe the best solution is one provided by technology: the insta-warrant. If the cops can conduct background searches from their squad cars, or analyze DNA on the spot, can’t they also be expected to check off a few boxes and zap a form to a duty judge via cellphone?

The point isn’t that the content of the insta-warrant application will reveal lots of relevant facts and circumstances to the judge. It’s that simply requiring the police to go through the motions of applying helps prevent abuse. Murphy favors the insta-warrant because it creates a record. “Getting a warrant means going on the record, making a statement under oath, and involving a judge—another person. That’s the safeguard.” If one cop in town is pulling over drivers regularly for little or no reason, his supervisor will be able to see that.

The insta-warrant, in one form or another, is surely how many police forces actually handle drunk-driving stops. After all, Mark Winder said he’d never had trouble getting a warrant, and he’d been a cop for 17 years. The warrant requirement can be made easy and still protect against abuse. “Look, no one thinks people should get away with drinking and driving because of a warrant requirement,” Murphy said. “But this is a case in which it seems like you can have your cake and eat it too.” She is talking about enforcing the law and respecting the Fourth Amendment. Let’s see tomorrow if the Supreme Court takes the same approach.