In a decision this past December, the Court held that a police officer may stop an individual based on a mistaken understanding of the law she believes that individual is violating, provided that the officer’s mistake of law is reasonable.  The decision is puzzling in its reasoning and its near-unanimity.

In Heien v. North Carolina, Sergeant Matt Darisse stopped Nicholas Brady Heien for driving a car with one broken brake light.  Over the course of the stop, Mr. Heien gave Sgt. Darisse consent to search the vehicle (whoops), and the sergeant discovered cocaine.  As it turns out, the proper interpretation of the relevant statute, N.C. Gen. Stat. Ann. § 20-129(g) (2007), reveals that it was perfectly legal for Mr. Heien to drive with one brake light, and that liability only arises when both brake lights are broken.  The question for the Court to resolve, then, was whether the stop was bad because, legally speaking, Sgt. Darisse had no basis to stop Mr. Heien, who was fastidiously observing North Carolinian traffic laws.  Oddly enough, the Court ruled that, even though Mr. Heien was abiding by the rules, Sgt. Darisse was reasonable in resolving an open question of law against Mr. Heien, and that the stop was good, and the fruits admissible.

By way of background, the existing state of affairs with regard to on-the-street police stops consists of the following.  Police officers may stop any person for any violation of any law where the officer has probable cause to believe that law was violated, without regard to the police officer’s underlying motive (even if the stop is racially motivated).  Whren v. United States, 517 U.S. 806 (1996).  Furthermore, that officer may conduct a full-custody arrest of that individual, regardless of how minor the offence is for which the individual was stopped.  Atwater v. City of Lago Vista, 532 U.S. 318 (2001).  Once that arrest is has begun, the officer has nearly unlimited power to conduct a search incident to arrest on the person, United States v. Robinson, 414 U.S. 218 (1973), and within the wingspan of the arrestee, Chimel v. California, 395 U.S. 752 (1969).  Finally, if the police officer is wrong about a fact relevant to the constitutionality of the search – say, whether the person consenting to entry does, in fact, have authority to consent – they are given some degree of leeway, provided the factual error is reasonable.  Illinois v. Rodriguez, 497 U.S. 177 (1990).  These cases essentially empower the police to make full-custody arrests for the sorts of minute violations of law individuals make on a daily basis, and to conduct searches thereto, and even allows them a margin of error with respect to the sorts of factual determinations that can make policing so difficult a task.

In Heien, the Court has added an yet another arrow in the police officer’s quiver: if they have stopped a person on a (reasonably) mistaken understanding of what is, and is not, unlawful, their action is not unreasonable, and is therefore not a violation of the Fourth Amendment.

The Court rested its reasoning on the “touchstone” of all Fourth Amendment questions: the reasonableness of the police action.  Because it was a reasonable error to have understood the governing statute to prohibit one faulty brake light, rather than only prohibiting two, the police officer acted reasonably in stopping Mr. Heien.  The Chief Justice almost flippantly observed, “to be reasonable is not to be perfect.”  (The Court also relied on an historical argument it had itself to acknowledge was largely inapposite: in the nineteenth century, officers could obtain qualified immunity from civil liability for reasonable mistakes of law in determining probable cause.  From this, the Court inferred that reasonable mistakes of law in determining probable cause had some bearing on the question whether the Constitution had been violated.  Yet, qualified immunity is very much beside the point as far as constitutionality is concerned.  That is to say, an officer may have violated the Constitution (the only relevent question in Heien), yet still be immune from suit.  See Harlow v. Fitzgerald, 457 U.S. 800 (1982).)

But what does Heien incentivize?  As Justice Sotomayor observed at oral argument, North Carolina’s position essentially means that whenever there is “any open question, police officers will rule in favor of their right to search.”  (Trans. 30:15-17.)  And, believe it or not, the meaning of a great deal of law – particularly the poorly-drafted legislation that governs everyday life – consists of “open questions.”  At first blush, Heien creates an incentive for the police (or well-informed police, anyway) to claim that a bad stop was, in fact, a good stop because their reasonable understanding of the law prohibited the arrestee’s conduct.

Worse than that, Heien does something new, and frightening, to the Fourth Amendment: it permits delegation of questions of law to police officers, in a context where the Fourth Amendment presumptively prohibits delegation of questions of fact.  The Court is wont to remind us that the presumption of Fourth Amendment activity is probable cause and the warrant, issued by a impartial judicial officer.  Katz v. United States, 389 U.S. 347, 357 (1967).  The warrant is based upon assertions of fact.  Where no exception to the warrant applies, and the police must seek a warrant, the Court will (one hopes) refuse to defer to the police: rather, their suspicions must be confirmed by the magistrate.

If the Fourth Amendment’s presumption is that we do not defer to the police on questions of fact, how much less should we defer to the police on questions of law?  Justice Douglas’s warning about the greater deference to the police on factual matters signaled by Terry resonates today:

To give the police greater power than a magistrate is to take a long step down the totalitarian path.  Perhaps such a step is desirable to cope with modern forms of lawlessness.  But if it is taken, it should be the deliberate choice of the people through a constitutional amendment.

Terry v. Ohio, 392 U.S. 1, 38 (1968).  Perhaps it is desirable that police be given latitude in interpreting the statutes that make up the bulk of everyday regulation.  I certainly don’t think so – the police have enough power as it is.  But that step should not have been taken by the Court, and it is deeply unsettling that only one Justice should have the courage to distance herself from it.