By Logan Dwyer, ACLR Featured Blogger 

This post, centered on State v. Heien,1 argues that searches or seizures based on a police officer’s mistake of law should be barred by the Fourth Amendment. To illustrate this problem, consider the following hypothetical, based on the facts in Heien.2 Suppose a police officer notices that one of the brake lights on a passing car is not working and, on the basis that a burned-out brake light violates the traffic code, pulls the car over. As the officer is writing the ticket, suppose the driver is acting suspiciously. Since the officer has probable cause to search the car—and because this is a criminal law blog—he does so and finds a kilogram of cocaine in the car.  

At the suppression hearing, our defendant has two lines of attack. First, it could be that the facts leading up to the search of the car or the stop do not rise to the level of reasonable suspicion.3 The defendant could argue, in this vein, that the officer was simply wrong—suppose that video evidence or a subsequent check of the car shows that both brake lights are fully operational. Unfortunately (for the defendant) a search or seizure based on an officer’s mistake of fact does not violate the Fourth Amendment unless the mistake was objectively unreasonable.4 Because of the deference due to police officers in their determinations of fact,5 this is a difficult burden to satisfy, and the defendant’s suppression motion will likely fail.  

On the other hand, our defendant could argue that even though the officer got all the facts right, the search and seizure were still unconstitutional owing to a mistake of law. Obviously, our hypothetical officer was correct that the kilogram of cocaine was illegal, but in some jurisdictions driving with a single brake light is perfectly legal.6 The question, then, is whether a search or seizure supported solely by a mistake of law is unconstitutional.7 

While this question has never be answered by the Supreme Court of the United States, four federal circuit courts and a number of state courts of last resort have struggled with the problem. The majority of courts have determined that a mistake of law cannot support a reasonable search or seizure under the Fourth Amendment.8 In Heien, North Carolina joined the minority of jurisdictions in holding that as long as an officer’s mistake of law is objectively reasonable, the mistake may support a search or seizure consistent with the Fourth Amendment.9 The Supreme Court of North Carolina used the totality of the circumstances test familiar to Fourth Amendment jurisprudence to determine the objective reasonableness of the officer’s mistake of law.10 Reasonableness, under this test, depends on the totality of the circumstances viewed by an objectively reasonable officer; as long as the surrounding context provides a particularized and articulable basis for suspecting criminal activity, reasonable suspicion exists.11 Insisting that reasonableness is a “commonsense” notion upon which “prudent men, not legal technicians, act,”12 the court concluded that the officer’s mistake of law was reasonable.13 In support of its analysis, the court offered two justifications.

First, it held that an inquiry into whether the mistake was reasonable was consistent with the Fourth Amendment’s general command that searches and seizures be reasonable.15 On the other hand, the court thought a bright-line test that would invalidate all searches and seizures performed because of a mistake of law would be inconsistent with the “nontechnical conception” of reasonable suspicion the Supreme Court has crafted.[xv] It noted that if mistakes of law were treated as categorically distinct from mistakes of fact, the result would be a significant change in test for reasonable suspicion. As a threshold matter, courts would need to determine if the officer made a mistake of law before getting to the totality of the circumstances test—a task made more difficult when law and fact seem to be connected.16

Yet this rationale is inconsistent with the Supreme Court’s use of the reasonable suspicion standard. As an initial matter, North Carolina’s approach would allow an officer to stop a citizen for violation of a law that did not exist, provided that the stop seemed justified at the time.17 This is intuitively incorrect, as verified by Terry and the rest of the Supreme Court’s reasonable suspicion jurisprudence. Under those cases, reasonable suspicion is more than a feeling that something bad might be afoot; officers must possess an articulable suspicion that the law has been, is, or is about to be violated.18 This required connection between suspicion and the law is the hallmark of the Fourth Amendment’s requirements, since it was ratified in light of the Founders’ concerns about the general and vague writs of assistance they had been subjected to under British rule.19 In other words, the reasonable suspicion standard binds officers to laws that actually exist, stopping them from acting based on whatever they would like the law to be.20

As to the Supreme Court of North Carolina’s doctrinal concerns, the majority of Fourth Amendment cases would pass this threshold inquiry easily. In those cases where defendants believably allege that an officer has made a mistake of law, finding searches that are based solely on a mistake of law per se unreasonable is justified by the difference between mistakes of law and fact. First, the scope of the law determines what mistakes of fact are reasonable for purposes of the reasonable suspicion inquiry. For example, whether an officer is mistaken about the severity of a crack in a windshield only matters if dangerously cracked windshields are illegal in the first instance.21

Furthermore, none of the reasons officers are allowed leeway in making mistakes of fact apply to mistakes of law. The Supreme Court has often remarked upon the high-risk, split-second determinations that officers are required to make in the field.22 Because they lack the opportunity for lengthy reflection or conference with other observers, officers get the benefit of the doubt when they make mistakes of fact. On the other hand, learning the scope of the law is presumably part of police officer’s basic training and ongoing education. This is a task that can be accomplished months in advance of an encounter with a suspect. Therefore, there is no urgency warranting deference to an officer who is mistaken about the law. Because the reasons we defer to officer’s reasonable mistakes of fact do not apply to mistakes of law, it makes sense to treat the former differently than the latter.

The Supreme Court of North Carolina’s second justification was that invaliding searches or seizures based solely on mistakes of fact would require police officers to predict subsequent judicial interpretations, “mandat[ing] that they be omniscient.”23 This is an echo of a concern raised by other courts which have endorsed the minority rule: requiring police officers to correctly interpret counterintuitive and complex statutes forces them outside their role as agents of the executive.24 The Court of Appeals in Heien, for instance, used a wide array of legal techniques to arrive at the conclusion that North Carolina’s brake light statute did not require two working brake lights; to expect the same of police officers is to expect them to be judges themselves.25

This rationale erroneously puts the blame for mistakes of law squarely on the shoulders of the mistaken officer. As mentioned above, however, an officer’s knowledge of the law is shared to some degree by the department responsible for her training.26 To the extent this is the case, the burden of clearly understanding what is illegal is spread across individual officers, their superiors, police department lawyers, and the like.27 While no institution can be expected to correctly determine what the law is all the time, the knowledge and resources possessed by police departments gives them a much more realistic chance than individual officers alone.

Furthermore, while the minority rule protects the judiciary’s power to interpret the law, it does little to protect the legislature’s right to create the law in the first instance. While interpreting the law is the province of the courts, creating the law is consigned to legislatures. Allowing police officers the ability to search and seize based on reasonable mistakes is functionally the same as giving police officers the ability to rewrite (or even create) statutes.28 Even when, as in Heien, an officer’s mistake is understandable,29 it is no less a revision of the statute. In a democratic system, technical flaws in statutes are for the legislature—not individual agents of the executive—to resolve.30 Indeed, as the dissent in Heien pointed out, the state legislature of North Carolina had already begun to update the brake light law between the Court of Appeal’s interpretation and the state Supreme Court’s review.31 The minority rule allows members of the executive to co-opt the powers of the legislature and should therefore be rejected.  

Despite the care the Supreme Court of North Carolina took in Heien, its conclusion was nevertheless incorrect. The real, tangible differences between mistakes of law and fact justify different treatment. This rule incentivizes mistakes of law on the part of the police. Knowing that a reasonable mistake is just as good as the law under this holding, some unscrupulous officers might refrain from clarifying their understanding of the law, preferring their own brand of justice over what is on the books.32 Moreover, departments might intentionally leave their officers in the dark in an attempt to increase the number of searches and arrests. Therefore, after the Supreme Court hears argument in Heien this coming October,33 it should reverse the Supreme Court of North Carolina and hold searches grounded solely on mistakes of law are per se unreasonable under the Fourth Amendment.