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Blood, Breath and the Fourth Amendment

Noah Feldman is a Bloomberg View columnist. He is a professor of constitutional and international law at Harvard University and was a clerk to U.S. Supreme Court Justice David Souter. His books include “Cool War: The Future of Global Competition” and “Divided by God: America’s Church-State Problem -- and What We Should Do About It.”
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What's the difference between blood and breath? This sounds like a theological question for the Holy and Great Council of the Orthodox Church that’s slated to meet in Crete this weekend. But it was the secular priests of the Supreme Court who took it up Thursday, in a case about warrantless blood tests and breathalyzers for drunk driving.

The court’s majority distinguished between the two kinds of blood-alcohol tests, banning warrantless blood tests because they are invasive while permitting breathalyzers because they aren’t. This compromise was criticized from the left and the right, and I doubt its legal correctness. But it was probably the only conclusion that the court could realistically reach given the dangers of drunk driving.

The opinion was written by Justice Samuel Alito and joined by Chief Justice John Roberts and Justice Anthony Kennedy as well as the court’s two liberal pragmatists, Justices Stephen Breyer and Elena Kagan. It focused on new state laws that make it a crime to refuse a blood-alcohol test rather than merely taking away drivers licenses.

The opinion emphasized not only the scourge of drunk driving but the success of state crackdowns in combating it; between the 1980s and 2015, deaths from drunk driving declined from an average of 25,000 per year to around 10,000. And it pointed out that there's a practical reason for new laws criminalizing the refusal to take a test: as punishment for drunk driving rises, more and more drivers are refusing to take the tests and accepting loss of their licenses in lieu of being tested and possibly sentenced for the crime of driving drunk.

The legal framework for both kinds of test, blood and breath, is the Fourth Amendment, which protects the people against “unreasonable searches and seizures” and provides that “no warrants shall issue, but upon probable cause.”

As interpreted by the Supreme Court, this amendment prohibits warrantless searches, except under exceptional conditions. One of those is called “exigent circumstances,” which means that the police can forego a warrant when there’s good reason to believe that evidence will be destroyed if they wait.

In 2013, the Supreme Court held that dissipation of blood alcohol is sometimes an exigent circumstance -- but not always. That blocked the court from ruling that either warrantless blood or breathalyzer tests are always allowed.

Instead the court had to rely on a different exception, known as “search incident to arrest.” This is a controversial exception these days, as the court showed when it split a few days ago over the constitutionality of a search incident to the discovery of an outstanding warrant after an unlawful arrest.

The court reviewed the history of the search incident to arrest exception. But unsurprisingly, nothing from the founding era sheds much light on blood-alcohol testing. So the court said it would follow a legal balancing test it framed more recently: it would weigh the degree to which a search "intrudes upon an individual’s privacy” against how much "it is needed for the promotion of legitimate governmental interests.”

The measure of intrusion into privacy laid the groundwork for treating blood and breath differently. The key differences for the court were invasiveness and the fact that so much more personal information can be gleaned from a blood sample, including DNA, than from a puff of breath.

The distinction makes sense. But the fact that a blood test is so clearly unconstitutional isn’t inherently a reason to hold that the breathalyzer is permissible.

Justice Sonia Sotomayor dissented from allowing warrantless breathalyzer tests, joined, as she was in the illegal arrest case, by Justice Ruth Bader Ginsburg. Her dissent began by dispelling the myth (which I for one needed dispelled) that most breathalyzers are given at the roadside. As it turns out, most are given at a police station, an average of 45 minutes after arrest. During the 45 minute lag, Sotomayor argued, police officers have ample time to get warrants.

What’s more, the time gap makes the “search incident to arrest” exception irrelevant, Sotomayor maintained. The point of the exception is to protect officers’ safety or prevent destruction of evidence. But no evidence is being destroyed, she said, notwithstanding the majority’s view that dissipation of blood alcohol is a type of unintentional but inevitable evidence-destruction.

Justice Clarence Thomas dissented alone, from the other side. He would have allowed blood tests as well as breathalzyers – but not as searches incident to arrest. Instead, Thomas would have overturned the 2013 precedent and held that the searches were allowed categorically as products of exigent circumstances.

As exercises in principled legal reasoning, both Sotomayor’s dissent and Thomas’s are superior to the majority opinion. The search incident to arrest is a bad fit for breathalyzers. Shoehorning the breath tests into the legal test distorts the doctrine, as both dissents argued. What’s more, it’s bad to weaken privacy rights just because drunk driving is dangerous. So are many other crimes that could be prevented or reduced if we did without that pesky right not to be searched whenever the cops want.

But at the same time, it’s easy to see why pragmatism drove the majority’s position. Forty-five minutes might be enough time to get a warrant on Law & Order, but a judge won’t always be happy to be roused in the middle of a holiday weekend to test every drunk driver.

The upshot may be that more states start making it a crime to refuse a breathalyzer test. That seems harsh – but objections will have to come through the political process, not the courts.

  1. All 50 states have laws saying that drivers implicitly consent to being tested on pain of losing their licenses.

This column does not necessarily reflect the opinion of the editorial board or Bloomberg LP and its owners.

To contact the author of this story:
Noah Feldman at nfeldman7@bloomberg.net

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Jonathan Landman at jlandman4@bloomberg.net