U.S. Supreme Court Considers Whether the Fourth Amendment Allows Reasonable Mistakes of Substantive Law: Part Two of a Two-Part Series of Columns

Posted in: Constitutional Law

In the first of this series of columns, which appeared here on Verdict on April 30, I discussed a case in which the U.S. Supreme Court recently granted certiorari, Heien v. North Carolina. That case raises the question whether a police officer may lawfully stop a vehicle on the basis of the officer’s having seen the driver do something that the officer reasonably but mistakenly believes violates state law. Most existing Supreme Court precedent on police error addresses mistakes of fact, rather than mistakes of law, the latter of which is presented in this case.

In the first column, I provided a background on the facts of Heien and the Fourth Amendment, and I discussed the differences between factual and legal errors. In this second column, I will further elaborate on the “good faith” exception to the exclusionary rule, which I predict the Court will hold applies to this case and as it does to other reasonable mistakes of law. Even if I am correct that the Court will continue to expand the “good faith” doctrine to avoid explicitly addressing Fourth Amendment questions, I suggest that doing so might narrow the scope of the Fourth Amendment’s protections nearly as effectively as deciding these cases directly on the substance of the Fourth Amendment.

The “Good Faith” Exception to Exclusion

In many situations, police “reasonably” act in violation of the Fourth Amendment, which the Court confusingly calls “good faith,” though it refers to objectively reasonable reliance rather than to subjectively good intentions (the ordinary meaning of “good faith”). In such situations, the Court has recognized an exception to the Fourth Amendment exclusionary rule and accordingly permits the admission of any resulting evidence at the suspect’s subsequent criminal trial, even though there might have been a Fourth Amendment violation.

The Court first announced the “good faith” exception to exclusion in United States v. Leon. The Court held that if it is reasonable to rely on what turns out later to have been a defective warrant, then police reliance on that warrant, though in violation of the Fourth Amendment, will nonetheless yield admissible evidence. This can occur if police have assembled factual evidence that they “reasonably” believe satisfies the legal probable cause standard, though the evidence they have assembled actually falls short of that standard, according to a later reviewing court. In this circumstance, the fact that there is a reasonable basis for believing in the validity of the warrant, coupled with police diligence in having sought a warrant and thereby observed the protective safeguard entailed in consulting a neutral magistrate, sufficiently redeems their conduct to permit the introduction of any resulting evidence.

A “good faith” error in this sort of case is best characterized as an error of law: though police have reason to think that what they have observed and gathered is sufficient to satisfy the legal standard of “probable cause,” it actually is not. Yet the evidence comes in.

A few years later, in Illinois v. Krull, the Court extended the “good faith” exception to cover cases in which police carry out a search or seizure pursuant to the authority of a statute that, a court later determines, violates the Fourth Amendment. Krull means that if a police officer “reasonably” searches or seizes on the basis of a statute that turns out to have authorized unconstitutional searches or seizures, the evidence that an officer finds as a result of the constitutional violation is nonetheless admissible in evidence at the suspect’s subsequent criminal trial. As in Leon, the sort of officer error at issue in Krull is best characterized as a legal error, because it stems from an erroneous understanding of what the U.S. Constitution has to say about a statute that authorizes searches or seizures. Yet the evidence comes in, despite a Fourth Amendment violation.

In Arizona v. Evans in 1995 and Herring v. United States in 2009, the Supreme Court held that if police carry out an arrest based on a warrant in whose existence they reasonably but mistakenly believe, then evidence found as a result of the arrest is also admissible under the “good faith” exception to the exclusionary rule. These cases involved computer databases that contained erroneous information indicating that there were warrants outstanding for the arrests of the respective suspects. As in the other good faith cases discussed here, the best account of these cases is that they involved errors of law. The police were in error about the existence of legal authorization from a magistrate for a seizure of the person (an arrest), but the evidence was admissible anyway.

Most recently, the Court held, in Davis v. United States, that an unconstitutional search of a vehicle incident to arrest, if conducted in objectively reasonable reliance on binding appellate precedent holding that the Fourth Amendment authorizes such searches, does not trigger application of the exclusionary rule. In the case in question, there was binding appellate precedent holding that the Fourth Amendment always permits the search of a vehicle, incident to an arrest of an occupant of the vehicle, even after the arrestee has been secured and cannot reach the vehicle. This turned out to be erroneous, under a U.S. Supreme Court case, Arizona v. Gant, which came down after the search took place but before Davis’s conviction became final. Nonetheless, it was “reasonable” for police, at the time of the search, to rely on binding appellate precedent going the other way.

In Heien, as in Davis, a police officer made a decision to carry out a search or seizure on the basis of a reasonable assumption that the law allowed it, but a later, unforeseeable judicial decision ruled that the law in fact rejected it. In Davis, the error concerned an interpretation of the Fourth Amendment itself, while in Heien, the error concerned an interpretation of the substantive traffic law. Yet in both cases, an officer acted on the basis of an erroneous but reasonable understanding of the governing law. It seems accordingly likely that the Supreme Court will see fit to apply its good faith exception to the exclusionary rule in this case rather than holding that police comply with the Fourth Amendment when they stop someone for violating a law that does not exist (but that the officer reasonably believes does exist).

The Impact of Ruling on the Basis of Good Faith

For purposes of deciding whether evidence resulting from the stop in Heien was admissible, it does not matter very much whether the Supreme Court decides that the search was reasonable (based on a reasonable mistake of law) or that even if the search was unreasonable, the error was made in good faith (because one could have reasonably interpreted the statute to prohibit driving with one broken brake light). Either way, the evidence comes in.

Nonetheless, the outcome I predict—that the Court will find a good faith exception for errors of law—will provide an opportunity for the current Court to marginalize the exclusionary rule again, as it has done many times before. The Court will likely repeat its views that (1) the Fourth Amendment does not require exclusion and that (2) exclusion of evidence is a costly measure that should be pursued only as a matter of last resort. When a police officer reasonably but erroneously interprets the traffic law to prohibit what a driver is doing, then—whether or not the officer violates the Fourth Amendment in doing so—there is no good reason to suppress reliable, probative evidence where the police did nothing deliberate, reckless, or even negligent, in acting as they did.

Deciding the case in this fashion, as I expect the Court will do, will have the benefit of avoiding the possibility of narrowing the scope of the Fourth Amendment itself. Rather than saying expressly that a police officer may lawfully stop someone for committing a nonexistent traffic offense, the Court would be limiting its discussion to the question of remedy and leaving the substantive issue open.

On the other hand, deciding the case in this fashion will also mean one more context in which no deterrent exists for Fourth Amendment violations. Certainly no one will be able to bring a lawsuit against a police officer (or a department) for stopping people who violate what the officer (or department) “reasonably” believes is the law. Thus without the exclusionary rule, where there is any margin for error, there is every incentive for police to “reasonably” interpret the law to prohibit what they want it to prohibit, rather than erring on the side of caution. Ironically, then, the Court’s continuing reliance on the “good faith” doctrine to avoid explicitly addressing Fourth Amendment questions might in reality serve to narrow the scope of the Fourth Amendment’s protections as effectively as a decision to do so expressly would have done.