Birchfield v. North Dakota: An Acceptable Compromise

Posted in: Criminal Procedure

In Birchfield v. North Dakota, the U.S. Supreme Court considered the question whether states may criminalize the refusal of a driver, arrested for driving while impaired, to take a test to measure his blood-alcohol level. The Court decided in this case that states may criminalize the refusal to take a breathalyzer test, which requires only that the suspect breathe into a machine. It decided as well, though, that states may not criminalize the refusal to take a blood test, absent a warrant, as an ordinary incident of an arrest for driving while impaired. The Court’s reasoning distinguishing between these two sorts of laws is sound, and it makes interesting points along the way, some of which are worthy of a critical second look.

Testing Alcohol as an Incident to Arrest

To answer the questions posed by Birchfield and its companion cases regarding criminalizing refusal, the Court turned first to the more basic question about the Fourth Amendment: would police violate the right to be free of unreasonable searches and seizures if, in the absence of a search warrant, they compelled a suspect to take a breathalyzer or a blood test after the suspect had been (lawfully) arrested for driving while impaired (DWI)? That is, rather than look first to what happens when a suspect refuses one or the other kind of test, the Court inquired about whether the Fourth Amendment protects suspects from having the tests imposed upon them. If the answer to that question is no—if there is no Fourth Amendment right against blood-alcohol tests of whatever sort—then the Court concluded that it would follow that there would be no problem with criminalizing the refusal to take the test. This falls under a more general principle that says that if a person has no right to do a particular thing, then the government may pass a criminal statute (subject to some limitations) prohibiting the person from doing that thing and criminally penalizing anyone who violates the prohibition.

In this case, then, the Court wanted to know whether there is a Fourth Amendment privacy right in being free of a BAC (blood-alcohol-content) test such that forcing the test on a suspected drunk driving arrestee against his will and in the absence of a warrant would violate his right against unreasonable searches. On this question, this Court answered “no” for breathalyzer tests and “yes” for blood tests. Why?


The Court looked at breathalyzers and determined that although a breathalyzer test is a search (and therefore must be reasonable, as a matter of Fourth Amendment law), it is not a very invasive test, in two distinct respects. First, it does not physically invade the body of the person very much. All the individual must do, to take a breathalyzer test, is breathe into a straw a few times. No one cuts into his body. No one removes parts of him that would otherwise stay put. Though privacy is at stake, it is at stake to a very limited and relatively insignificant degree.

In a second sense as well, the breathalyzer test is not very invasive. When police perform a breathalyzer test, they do not learn anything about the suspect other than what his BAC is. Taking his breath through a breathalyzer, then, does not expose facts about his medical history, any illnesses he might have, or anything else that could be personal and that he might worry would be used against him in some unspecified way in the future. This is an important point, because the Court generally does not dwell on informational privacy when it is considering the intrusiveness of particular searches and seizures, but here, it pays attention to the limited nature of the information disclosed by a breathalyzer test.

Part of its decision to approve the breathalyzer involved not only a look at the invasiveness of the test but also a consideration of its benefits or the government’s need for it, as part of the “reasonableness” balancing test that it chose to apply in this case. The Court emphasized the importance of gathering information about intoxicated driving, because such driving poses a terrible threat to the public safety and takes a tremendous toll in the form of serious injuries and deaths. Furthermore, once a person has stopped drinking, his natural metabolism begins to break down the alcohol in his system. Therefore, taking a breath test of his BAC as an ordinary incident of arrest will ensure that the evidence of his intoxication is not lost or metabolized away so that it cannot be used to prove at trial that he was driving while impaired.

The Court compared the loss of alcohol evidence in this way to the threats that more typically account for the authority to “search incident to arrest” a suspect’s person and the area within his immediate control. Such automatic authority exists because an arrest generates the risk that a suspect will either reach for a weapon or attempt quickly to destroy evidence that might be used against him. The latter concern, the Court found, maps nicely onto the worry about metabolization of alcohol, and the fact that one type of “destruction of evidence” is deliberate while the other type is biologically automatic is inconsequential. Therefore, under the Court’s holding in Birchfield, police may impose a breathalyzer test on a suspect arrested for driving while impaired, without having to first obtain a warrant. And accordingly, the Court said, a state may legitimately criminalize a suspect’s refusal to undergo a breathalyzer as an incident to a lawful arrest.

Blood Tests

The Court concluded, however, that blood tests are different. The difference lies again in two different domains, the physical and the informational. When police take blood from a suspect, they cut into his body and they remove tissue from it that would otherwise (unlike exhalations of breath) remain inside his body. In addition to this physical invasiveness characteristic of a blood test for alcohol, there is also an informational exposure that accompanies a blood test (and that does not similarly accompany a breath test). If police have a person’s blood, they can find out all sorts of personal information about that individual that is encoded in his blood and that may have nothing to do with whether he was intoxicated while driving. Knowing of this exposure, a person from whom blood is taken may experience anxiety of a sort that would not be experienced by someone who has exhaled into a breathalyzer machine. On the invasiveness dimension, then, a blood test scores high enough to give rise to concerns on the part of the Court for the suspect’s Fourth Amendment interest in privacy.

After looking at invasiveness, the Court again looked at the benefits and corresponding necessity of a blood test for alcohol, just as it did with the breath test. This time, however, the Court concluded that there is generally no need for a blood test, because there is a less invasive alternative (and also highly accurate) breath test that can be performed instead. This analysis, like the Court’s consideration of informational privacy in its invasiveness analysis, is somewhat unusual for the Court. Generally speaking, the Court does not look at “less restrictive alternatives” when it is considering whether to approve a search or seizure under the Fourth Amendment. In this case, however, in part because an unusually invasive test is involved (a blood test) and in part because there is an obvious, ready alternative of the breath test, the Court decided to prohibit the automatic blood test as an incident to arrest in the absence of a warrant (or some exigent circumstance excusing the absence of a warrant).

The Court acknowledged, in deciding as it did, that sometimes, it may be necessary to take blood rather than use a breathalyzer. For example, if a suspect is unconscious, a breathalyzer test is not an option, and it is also true that a suspect must cooperate in order for the police to perform an accurate breathalyzer test. But in situations where a blood test is necessary, the Court said, police can procure a warrant (or cite an exigency for failing to do so), and most of the time, it will not be necessary to perform a blood test at all. In the garden-variety DWI arrest case, then, the Court found that the ready availability of a breath test plays an important role in precluding the automatic legality of a blood test. As a result as well, the law may not criminalize the refusal to take a blood test, absent a warrant, as an automatic incident of an arrest for DWI.

Birchfield, Bernard, and Beylund

The case before Court involved three differently situated complainants who challenged the legality of their respective states’ refusal statutes. The Court went on to resolve each of the individual cases in a manner that reflected its decision about the legal availability of BAC tests as part of a search incident to arrest for DWI. Police told Birchfield that he had to take a blood test or face criminal penalties, and he refused to take the blood tests and was criminally prosecuted for it. Consistent with its decision that blood tests may not be forced upon an arrestee without a warrant (or exigent circumstances), the Court held that Birchfield should not have been criminally prosecuted for his refusal.

The second individual before the Court, Bernard, challenged a legal prohibition against breathalyzer refusal. Because the Court held that the Fourth Amendment does not protect individuals against automatic breathalyzers as an incident to a DWI arrest, the Court said that the criminal prosecution of Bernard was legitimate.

Finally, in the case of the third perosn before the Court, Beylund, he had been told that he had to submit to a blood test or else be criminally prosecuted for refusing to do so. As a result (at least in part) of this threat of criminal prosecution, Beylund agreed to the blood test, and the results were highly incriminating in his prosecution for DWI. In his case, the Supreme Court remanded for a determination of whether or not Beylund had provided a voluntary consent to the blood test, given the totality of the circumstances, which included his having been told inaccurate information about the consequences of refusing to take a blood test (namely, that he could be criminally prosecuted for it). The Court indicated that even if it were determined that he did not voluntarily consent to the blood test, it might or might not be the case that the evidence of his blood test should have been suppressed.

What we see from the Court’s disposition of the three specific situations that it confronted is that the smart decision on the part of a suspect who believed strongly that he had the right to refuse a BAC test would be to actually refuse the test. This way, if it turned out that he had the right to refuse, then he could not be punished for that refusal. If he instead gave in to the threat, as Beylund did, he might end up successfully prosecuted using evidence that the State had no right to obtain. This is a function of the very forgiving “totality of the circumstances” test of the voluntariness of consent, a standard under which a threat of criminal prosecution might not amount to sufficient coercion to undermine consent. It is also a function of the Court’s hostility to the suppression of reliable evidence.


Justices Sotomayor and Thomas concurred in part and dissented in part from the Court’s decision. (Justice Thomas concurred in part in the judgment, to be more precise). Not surprisingly, Justice Sotomayor’s position was that she agreed with the decision to prohibit a blood test incident to arrest, while Justice Thomas agreed with the decision to permit a breath test. Each justice, however, believed that both blood and breath refusal situations should have been resolved the same way. So Justice Sotomayor would have prohibited a breath test incident to arrest and Justice Thomas would have permitted a blood test (as well as a breath test), because of the exigent circumstance presented by a DWI suspect metabolizing alcohol with every passing minute.

Each justice has a point in this case. Justice Sotomayor correctly observes that breath tests are generally performed quite some time after the individual is arrested for DWI. This is important because it does not take very long for the police to obtain a search warrant (less time, it turns out, than it typically takes to get to doing the breath test). Therefore, requiring a search warrant for a breath test, explains Justice Sotomayor, would generally not lead, relative to no warrant requirement, to the loss of evidence due to the metabolization of alcohol by the suspect. To the extent that the point of allowing breath tests as an automatic incident to arrest is to serve the need to avoid losing evidence that might otherwise be lost, Justice Sotomayor is right that the quick warrant turn-around time (coupled with the longer time it typically takes to get to do a breath test) makes the breath test seem largely unnecessary. And in the rare case in which it is necessary, she persuasively argues, police can obtain a warrant or cite an exigency for failing to do so.

Assisting Justice Thomas, the majority also makes a good point, however (regarding breath tests but equally applicable to blood tests). Obtaining a warrant for a BAC test, unlike getting a warrant for other sorts of searches and seizures, will be a fairly standardized matter. Police will cite a suspect’s slurred speech, his smelling of alcohol, his failure to walk in a straight line, his swerving on the highway, and other such indices of intoxication. Because the indices of intoxication are so standardized, the magistrate who issues a warrant does not add much in reviewing the officer’s assessment of probable cause to perform a BAC test, and that is true whether it is a breath test or a blood test. And I would add that if a blood test is so intrusive, then why may police perform such a test just by getting a warrant that attests to their having probable cause, a matter that is so standardized in the context of DWI, as the Court argues? If magistrates have little to contribute in this context, then perhaps Justice Thomas is right to remove warrants from the equation and rely on exigent circumstances (though there is, in fact, no real exigency).

All in all, though, I think the Court made the right choice in “splitting the baby” between the two different types of BAC tests. Breath tests are not terribly intrusive, and their results are almost always important enough to a DWI prosecution that police should perhaps be spared the need to seek a warrant in every case, especially given the standardized nature of probable cause for DWI. At the same time, blood tests are intrusive, both physically and informationally, and the need to get a warrant for them—though achievable with only probable cause—will encourage police to do a breathalyzer instead whenever practical. That suspects can be criminally prosecuted for refusing a breath test, moreover, will mean that one way or the other, a person arrested for and guilty of DWI will be successfully criminally prosecuted, either for the DWI itself or for refusing a breath test. Given the grave public health harm of DWI, this is not a bad result.

One response to “Birchfield v. North Dakota: An Acceptable Compromise”

  1. Joe Paulson says:

    Good analysis. Basic point is that this is incident to an arrest / there is some basic reasonableness weighing going on — so it is not like some power to give random breathalyzer tests … encouraging them over blood tests is also a positive … finally, states can put higher barrier if desirable. Also, if tests for whatever reason are more revealing — some ability, e.g., to analysis the spit for DNA etc., a stricter rule might be warranted.

    Given my druthers, I think Sotomayor is correct, but the bottom line here is acceptable.