Wayne A. Logan | 77 Vand. L. Rev. 1

In Heien v. North Carolina, the Supreme Court held that individuals can be seized on the basis of reasonable police mistakes of law. In an opinion authored by Chief Justice Roberts, the eight-Justice majority held that the Fourth Amendment’s prohibition of “unreasonable” seizures does not bar legally mistaken seizures because “[t]o be reasonable is not to be perfect.” Concurring, Justice Kagan, joined by Justice Ginsburg, emphasized that judicial condonation of police mistakes of law should be “exceedingly rare.” In a solo dissent, Justice Sotomayor fairly “wonder[ed] why an innocent citizen should be made to shoulder the burden of being seized whenever the law may be susceptible to an interpretive question.”

This Article provides the first empirical study of state and lower federal court cases applying Heien (from the day it was decided in mid-December 2014 through mid-June 2023). Of the over 270 cases examined, a large majority (over two-thirds) deemed unlawful police seizures reasonable, belying Justice Kagan’s expectation that such cases would be “exceedingly rare.” Moreover, the study makes clear that Heien is being applied well beyond the context in which it arose—an auto stop for a suspected equipment violation. Courts regularly rely on Heien to justify unlawful stops for a broad array of other, often more serious offenses and to justify unlawful arrests of individuals, far more significant intrusions on physical liberty that allow officers to conduct searches. Courts also forgive police mistakes of law regarding Fourth Amendment doctrine, such as the contours of consent and the permissibility of warrantless blood draws. Finally, the study demonstrates that courts lack any consistent analytic rubric for assessing whether a police mistake of law is reasonable, including the critically important foundational question of who (judges, laypersons, or police) should serve as the benchmark “audience” when assessing whether a mistake of law is reasonable.