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

Posted in: Constitutional Law

Last week, the U.S. Supreme Court granted certiorari in the case of Heien v. North Carolina. Heien raises the issue of whether a stop is lawful, for Fourth Amendment purposes, when the basis for the stop is the officer’s having seen the driver do something lawful that the officer reasonably but mistakenly believes violates state law. Described differently, the question is whether the Fourth Amendment protects against stops by a police officer who acts on the basis of a reasonable but erroneous interpretation of state law. Different courts of appeals have arrived at distinct conclusions on this issue, so the Court will be resolving a circuit split in answering what turns out to be a difficult Fourth Amendment question.

In this first of a series of two columns, I will discuss the facts of Heien, explain what “reasonable seizures” are under the Fourth Amendment, and describe the differences between legal and factual errors. In the second column, which will appear on Verdict on May 5, I will discuss the “good faith” exception to the exclusionary rule as well as the impact of a ruling on the basis of good faith.

Facts of Heien

In Heien, a police officer pulled over a vehicle in which the right rear brake light initially failed to illuminate when the driver engaged the brakes. The officer interpreted the existing traffic law to prohibit driving a car with one non-functioning brake light. The state court of appeals later determined, however, that the traffic law actually requires only one working brake light and that the officer who stopped the car therefore had no valid reason for the stop. This interpretation conflicted with what others had reasonably understood to be the meaning of the statute.

Had the driver of Nicholas Brady Heien’s car been charged with a traffic violation, the case would have been dismissed, under the court of appeals’ interpretation of the statute. One cannot, after all, be guilty of violating a legal requirement that does not exist. After pulling over the driver, however, the officer in the case asked for and received consent from both driver and passenger (Heien) to search the vehicle, and the subsequent search turned up cocaine. Heien was then arrested and charged with trafficking in cocaine, on the basis of the evidence found during the search of the vehicle.

Given the state court of appeals’ interpretation of the statute, the defendant argued that the evidence at issue should have been suppressed as the fruit of an unlawful stop. What made the stop unlawful? The fact that it happened without any reasonable suspicion that something unlawful had occurred or was about to occur, the standard for validating a brief stop, under the Supreme Court’s decision in Terry v. Ohio.

The Meaning of “Reasonable Seizures” Under the Fourth Amendment

The Fourth Amendment protects people’s right to be secure against “unreasonable . . . seizures.” Among other things, this gives people a right to liberty from detention by the government (i.e., liberty from “seizures of the person”) absent a valid basis for their detention. For police to lawfully conduct a brief stop of a suspect, the Supreme Court has held that they must have a “reasonable suspicion” that unlawful activity is in progress or has been committed.

Reasonable suspicion is a less rigorous standard than what is needed for an arrest, which generally requires “probable cause” to believe that a crime has taken place. While more lenient than probable cause, however, “reasonable suspicion” still demands that police have some factual basis for suspecting a violation of the law before detaining an otherwise free person, even for a short time.

Within this legal framework, a police officer might stop a driver who is weaving from side to side in traffic. In this situation, police could reasonably suspect that the driver is intoxicated, and driving while intoxicated is against the law. It could turn out that the driver is not intoxicated but was weaving because she is a relatively new driver.

Still, the stop would be legally valid, and if the police saw narcotics in plain view during the stop, those drugs would accordingly be admissible against the driver in a subsequent drug-related criminal prosecution. Police, in other words, can be mistaken in their suspicions without thereby violating the Fourth Amendment requirement that they act “reasonably.”

In Heien’s case, the problem is that what the police reasonably suspected (driving with a broken brake light) turned out to be lawful activity, under the state court of appeals’ interpretation of the law at issue. To “reasonably suspect” lawful activity does not ordinarily justify a seizure, so the police in this case might have violated the Fourth Amendment. If so, then the evidence that turned up during a consent search on the heels of the stop might represent “fruit of the poisonous tree,” inadmissible against Heien in his prosecution for cocaine trafficking.

An Easy Case

Consider what an easy case of police error would look like. Assume that the law permits people to play music while they drive. A police officer is driving on the highway and hears the sounds of radio music (The Grateful Dead) emerging from a car driven by John Doe. The officer now has “reasonable suspicion” to believe that the driver is playing music in his vehicle while driving. Absent some other objectively reasonable basis for pulling over John Doe, however, the police officer in this situation may not stop Mr. Doe without violating the Fourth Amendment. This is true, moreover, even if the officer happens to believe (without a good reason) that it is illegal to play music while driving.

Take a different scenario. Now the officer believes that John Doe is committing an actual offense, such as driving while intoxicated, but the officer lacks any adequate factual grounds for that belief. Perhaps the officer again hears Grateful Dead music coming out of the car. The officer (unreasonably) concludes that listening to the Grateful Dead provides strong evidence of intoxication. If the officer pulls over Mr. Doe on the basis of this conclusion, then—absent some independently valid basis for the stop—she will be violating the Fourth Amendment.

For a stop to comply with the Fourth Amendment, then, requires both that the facts support a conclusion that the person to be stopped is doing or has done some act (X) and that X be illegal. But what happens when X is legal and the officer reasonably (though incorrectly) believes that X is illegal? That is the question presented by this case.

In an important sense, the two hypothetical scenarios above, in both of which the officer lacks reasonable suspicion of criminal activity, are essentially the same. Having “reasonable suspicion” to believe that a driver is doing something legal is the same thing as having “no reasonable suspicion” to believe that the driver is doing something illegal. In these two scenarios, hearing Grateful Dead music coming from the vehicle plays both roles—it is good evidence that the driver is listening to music while driving (which is legal), and it is inadequate evidence that the driver is driving while intoxicated (which is illegal). Any time police lack reasonable suspicion to justify a stop, it will always be the case that they simultaneously (1) have a factual basis for believing that the driver is doing something lawful (e.g., driving at the speed limit), and (2) lack a factual basis for believing that the driver is doing something unlawful.

Reasonable but Mistaken Factual Beliefs

Fourth Amendment doctrine has always and necessarily tolerated errors by police officers. Police, like other humans, are imperfect and therefore will sometimes carry out valid searches or seizures that turn up nothing, particularly given the relatively permissive standards of “probable cause” and “reasonable suspicion” that authorize searches and seizures.

Police might, for example, have probable cause to believe that Jane Roe robbed a bank and that she is hiding the fruits of that crime in her knapsack. (Say an eyewitness to the robbery identified Jane in error.) In such a case, police will be able to obtain a warrant to arrest Jane in her home and to seize and search Jane’s knapsack for the proceeds of the robbery.

The fact that Jane is actually innocent of the robbery does not in any way negate the “reasonableness” of what the police do. The Fourth Amendment does not require that police be factually correct in their suspicions every time they carry out a search or seizure. It requires only that police always behave reasonably when they carry out searches or seizures.

In what contexts are errors acceptable? Generally, “reasonable” police errors have concerned the facts. As in the description above, police may have gathered sufficient evidence (through witnesses or observations) to warrant the conclusion that a particular person committed a crime and/or that evidence of crime may be found in a particular location. If so, and if police obtain a warrant (in those cases in which a warrant is required), then they have complied with the dictates of the Fourth Amendment, even if it turns out that they were mistaken about the facts and that the suspect at issue is innocent and/or the location in question does not contain the predicted evidence.

Reasonable Legal Errors

On the North Carolina Supreme Court’s approach, police who briefly stop a suspect comply with the Fourth Amendment so long as they reasonably—even if mistakenly—believe that what they witnessed evidences the suspect’s having violated an actual law. In the U.S. Supreme Court’s case law, however, the reasonable errors that the Court finds to have complied with the Fourth Amendment have typically been errors of fact and not of law. In this sense, the officer who “reasonably believes” that driving with music on is illegal is in uncharted territory, as is the officer who erroneously but reasonably believes that driving with only one working brake light is illegal.

One could argue, as the North Carolina Supreme Court maintains, that being reasonably mistaken about the law is really no different from being reasonably mistaken about the facts. When police believe, with good reason, that the law has been violated, then they may act—whether their mistake turns out to be one of law or one of fact. As we saw above, for example, an officer who stops someone playing music in his car because the officer believes that playing music is illegal is making the same sort of mistake as the officer who stops someone playing music in his car because the officer believes that playing (Grateful Dead) music evidences intoxication.

To support this position, the North Carolina Supreme Court cites a U.S. Supreme Court case that approves an arrest for violating an ordinance that was subsequently declared unconstitutional. In Michigan v. DeFillippo, police arrested a man for violating an ordinance, and the (otherwise lawful) search incident to arrest that followed turned up evidence of a drug offense, for which the man was charged. On appeal, the Michigan Court of Appeals held that the ordinance that the man had violated was unconstitutionally vague. Nonetheless, the U.S. Supreme Court ruled that the arrest was valid, because it was made on the basis of “good faith” reliance on a presumptively valid statute. This case might seem effectively to dispose of Heien, since the officer in Heien, like the police in DeFillippo, reasonably relied on what turned out to have been an incorrect but reasonable reading of the law.

Good Faith

The problem with this equation of factual and legal errors is that ever since 1984, when police have made reasonable legal errors rather than reasonable factual errors, the U.S. Supreme Court has ruled on the admission of resulting evidence on the basis of the “good faith” exception to the Fourth Amendment exclusionary rule rather than finding actual compliance with the Fourth Amendment. Because DeFillippo was decided before the good faith doctrine was born, its applicability to the scenario in Heien might be supplanted by the more recent, more properly applicable good faith doctrine. The reasoning in DeFillippo, moreover, may be harmonized with that underlying the good faith doctrine. After all, although the Court in DeFillippo relied on the Fourth Amendment itself rather than on a good faith exception to exclusion, it expressly used the phrase “good faith,” which could help link that decision with the later-developed good faith doctrine.

In Part Two of this series of columns, I will explain how the Court developed the “good faith” exception to the exclusionary rule and the possible implications of the Court’s using the good faith doctrine to decide Heien.