Blog. Blog. Blog.

Reasonable, Not Perfect: Does the Fourth Amendment Permit Mistakes? (May 30, 2016)

The Fourth Amendment of the U.S. Constitution prohibits “unreasonable” searches and seizures.[1] By implication, it permits reasonable searches and seizures. So, what if police conduct searches and seizures based on mistakes of fact or law? Is that reasonable under the Fourth Amendment?

After all, police are not perfect; they can and do make mistakes. Some of those mistakes relate to factual issues, such as whether someone has authority to consent to the search of a home or whether someone who matches a suspect’s description is, in fact, the suspect. Others relate to legal issues, such as whether a legal prohibition applies to certain conduct or, if so, whether the conduct falls within the scope of the prohibition. Can a mistake along these lines be reasonable? Does it matter whether the mistake is factual or legal?

The U.S. Supreme Court has recognized, time and again, that mistakes can be reasonable under the Fourth Amendment. If so, a search or seizure based on the mistake is not unreasonable and thus does not violate the Amendment’s prohibition on unreasonable searches and seizures. Notably, the Court has held that both factual and legal mistakes can be reasonable, depending on the circumstances.

The Court has, for decades, acknowledged that searches and seizures based on mistakes of fact can be reasonable. Although the Fourth Amendment allows for some mistakes by police, giving them “fair leeway for enforcing the law in the community’s protection,” the Court has said “the mistakes must be those of reasonable men.”[2] In other words, the mistake must be that of an objectively reasonable person. The Court has repeatedly recognized that factual mistakes can meet this standard.

For example, in Hill v. California, police had probable cause to arrest a suspect but mistakenly arrested someone else who matched the suspect’s description; under those circumstances, the Court held that the factual mistake about the arrestee’s identity was reasonable and, hence, neither the seizure nor the accompanying search of the arrestee was unlawful.[3] Similarly, in Illinois v. Rodriguez, the Court noted that the warrantless search of a home is lawful if a resident consents to the search; the Court then held that the search in question remained lawful even though police obtained the consent of someone who reasonably appeared to be, but was not in fact, a resident.[4] These precedents make plain that searches and seizures based on factual mistakes do not run afoul of the Fourth Amendment, so long as those mistakes are objectively reasonable.

More recently, in Heien v. North Carolina, the Court held that searches and seizures based on mistakes of law can also be reasonable.[5] A nearly unanimous Court saw no principled reason why legal mistakes could not be reasonable too, just as factual mistakes can be reasonable.[6] Nothing in the text of the Fourth Amendment or the relevant caselaw requires the Court to treat mistakes of law, categorically, as per se unreasonable. Indeed, according to the Court, Heien presented a clear-cut example of an objectively reasonable mistake of law that did not run afoul of the Fourth Amendment.

In Heien, a police officer stopped a driver because the driver’s vehicle had only one operable brake light, not two. The officer believed the absence of the second brake light was a traffic violation under North Carolina law, which violation gave him a basis for the traffic stop. A state court later held that, because the applicable law required only one operable brake light, the driver had not committed a traffic violation and the investigatory stop was based on a mistake of law. But the U.S. Supreme Court held that the traffic stop nonetheless did not violate the Fourth Amendment, even though it arose from a mistake of law.

Based on the relevant textual reference to “unreasonable” searches and seizures, the Court in Heien reaffirmed that the Fourth Amendment does not require perfection, only reasonableness.[7] In other words, “the ultimate touchstone of the Fourth Amendment is reasonableness.”[8] The routine traffic stop in Heien was a “seizure” within the meaning of the Fourth Amendment but, because the stop was an investigatory stop rather than a formal arrest, police could conduct the stop without “probable cause,” so long as they had “reasonable suspicion”—that is, “a particularized and objective basis for suspecting the particular person stopped of breaking the law.”[9] The Court then addressed whether a mistake of law could give rise to reasonable suspicion.

The Court held that it could. Indeed, Heien stands for the plainly stated proposition that “reasonable suspicion can rest on a [police officer’s] mistaken understanding of the scope of a legal prohibition.”[10] And Heien announced a rule for lower courts to follow: If “it was reasonable for an officer to suspect that the defendant’s conduct was illegal[,] . . . there was no violation of the Fourth Amendment in the first place.”[11] The Court held that the officer’s mistake of law in Heien was reasonable because that law had “never been previously construed by North Carolina’s appellate courts” and was ambiguous enough to bear the officer’s mistaken interpretation.[12] Therefore, Heien was the first case in which the Court specifically recognized that police’s mistaken understanding of the law could, in certain cases, be reasonable and thus not run afoul of the Fourth Amendment.

The bottom line is that reasonable mistakes—both factual and legal—do not violate the Fourth Amendment right against unreasonable searches and seizures. The question is not whether the mistake is factual or legal, but whether the mistake is objectively reasonable. Admittedly, the answer is not always clear; but, in many cases, it is.

_______________________

[1] U.S. Const. amend. IV.

[2] Brinegar v. United States, 338 U. S. 160, 176 (1949).

[3] 401 U. S. 797, 802–805 (1971).

[4] 497 U. S. 177, 183–186 (1990).

[5] 135 S. Ct. 530, 536 (2014).

[6] Id. (Roberts, C.J., joined by Scalia, Kennedy, Thomas, Ginsburg, Breyer, Alito, and Kagan, JJ.) (“[R]easonable men make mistakes of law, too . . . . There is no reason, under the text of the Fourth Amendment or our precedents, why [searches and seizures] should be acceptable when reached by way of a reasonable mistake of fact, but not when reached by way of a similarly reasonable mistake of law.”); cf. id. at 541 (Kagan, J., concurring) (noting that a mistake of law will be reasonable only in exceptionally rare cases). But see id. at 543 (Sotomayor, J., dissenting) (arguing that mistakes of law cannot be reasonable).

[7] Id. at 536 (“To be reasonable is not to be perfect[.]”).

[8] Id. (internal quotation marks omitted; emphasis added).

[9] Id. (internal quotation marks omitted).

[10] Id.

[11] Id. at 539.

[12] Id. at 540.

I have made this blog available for educational purposes only, not to provide specific legal advice. By using this blog, you understand that there is no attorney–client relationship between you and me. This blog should not be used as a substitute for independent legal advice from a licensed professional attorney in your state.