Reasonable Mistake of Law as a Basis for Terry Stops in Felon-in-Possession Prosecutions

Introduction

United States v. Justin Jamaal Nettles, decided by the Eleventh Circuit on June 3, 2025, confronts the limits of a law enforcement officer’s authority to conduct an investigative stop under the Fourth Amendment when the officer is operating under a reasonable mistake of law. The Defendant–Appellant, Justin Jamaal Nettles, was convicted of being a felon in possession of a firearm after police stopped him at a gas station, discovered a loaded handgun in his vehicle, and later learned that he was a prohibited possessor. Mr. Nettles moved to suppress the firearm evidence, arguing that the stop exceeded the scope of a consensual encounter and that, in any event, the officer lacked reasonable suspicion because he misinterpreted Florida’s remote-start exception to its “unattended vehicle” statute.

The key issues presented were (1) whether the initial encounter was consensual or rose to the level of a seizure requiring reasonable suspicion, and (2) whether the officer’s misunderstanding of the remote‐start exception to Fla. Stat. § 316.1975(1) invalidated any reasonable suspicion for a Terry stop. The Government defended the stop as valid under Terry v. Ohio and under Heien v. North Carolina, which allows stops based on reasonable mistakes of law. The Eleventh Circuit affirmed the denial of the suppression motion and Nettles’s conviction.

Summary of the Judgment

The Court began by reviewing Fourth Amendment protections against unreasonable searches and seizures, emphasizing that Terry stops require “reasonable suspicion” of criminal activity based on specific and articulable facts. It held that when officers encounter a suspect whose vehicle is idling with the engine on and headlights illuminated—and who cannot produce a valid license—an objectively reasonable officer may suspect a violation of the state’s prohibition on unattended motor vehicles with running engines.

Although Florida law exempts vehicles equipped with remote‐start systems, the officer did not know of Mr. Nettles’s remote key fob at the time of the stop. Under Heien, a reasonable mistake of law is permissible so long as the mistake itself is objectively reasonable. The Court concluded that the officer’s misunderstanding of the statute was reasonable and did not undermine the validity of the stop. The Court therefore affirmed the district court’s denial of the suppression motion and sustained Nettles’s conviction for felon in possession of a firearm.

Analysis

Precedents Cited

Terry v. Ohio, 392 U.S. 1 (1968): Established the standard for investigative stops—an officer may conduct a brief, warrantless detention if there is reasonable suspicion of criminal activity.
Adams v. Williams, 407 U.S. 143 (1972): Reinforced that officers need not wait for probable cause to prevent a crime or apprehend fleeing suspects.
Illinois v. Wardlow, 528 U.S. 119 (2000): Clarified that reasonable suspicion requires more than an unparticularized hunch.
Florida v. Royer, 460 U.S. 491 (1983) and Rodriguez v. United States, 575 U.S. 348 (2015): Explained scope and duration limits on Terry stops and what inquiries are permissible.
Heien v. North Carolina, 574 U.S. 54 (2014): Held that an officer’s reasonable mistake of law can give rise to reasonable suspicion for a Terry stop.
Eleventh Circuit cases such as Perez, 443 F.3d 772 (2006), Lewis, 674 F.3d 1298 (2012), and Holt, 777 F.3d 1234 (2015): Set standards for deference to district court findings and the totality-of-circumstances test for reasonable suspicion.

Legal Reasoning

The Court applied a mixed‐question standard: factual findings by the district court are reviewed for clear error, legal conclusions de novo. It first determined that when Mr. Nettles exited the convenience store to find his car idling with the engine engaged, he was seized under Terry because a marked patrol car had activated its lights and two officers approached him.

Under the “totality of the circumstances,” the idling vehicle, the lack of a visible operator, and Nettles’s failure to produce a valid license supplied specific and articulable facts supporting reasonable suspicion of a statutory violation. Even though the remote‐start exception would have excused the conduct, that exception was not known to the officer at the time of the stop.

The pivotal holding drew on Heien’s acceptance of reasonable legal mistakes: as long as a mistake of law is objectively reasonable, it does not vitiate reasonable suspicion. The Court found the officer’s interpretation of the Florida statute plausible and consistent with common understandings of an “unattended” vehicle.

Impact

This decision reinforces and clarifies the scope of Terry stops within the Eleventh Circuit, particularly:

Law enforcement officers may rely on reasonable—even if incorrect—interpretations of statutes when forming reasonable suspicion.
The decision underscores the importance of totality‐of‐circumstances analysis over hyper-technical parsing of statutes at the moment of a stop.
Future defendants will face a higher hurdle in suppressing evidence where officers can articulate an objectively reasonable misunderstanding of legal provisions.

It also highlights the continued vitality of Heien and may prompt police training programs to stress the boundaries of legally cognizable mistakes of law.

Complex Concepts Simplified

Reasonable Suspicion vs. Probable Cause: Reasonable suspicion is a lower standard than probable cause; it requires specific, articulable facts suggesting criminal activity, not proof that a crime has probably occurred.
Terry Stop: A brief investigative detention based on reasonable suspicion, limited in scope and duration to address the reason for the stop.
Fruit of the Poisonous Tree: A doctrine that excludes evidence obtained by unconstitutional means, but does not apply when the underlying stop is valid—even if based on a reasonable legal mistake.
Objective Reasonableness of Mistake of Law: Under Heien, an officer’s misunderstanding of statutory language can ground reasonable suspicion if the error would be made by a prudent, competent officer.

Conclusion

United States v. Nettles reaffirms that under the Fourth Amendment and Eleventh Circuit precedent, an officer’s reasonable mistake of law may supply the necessary reasonable suspicion to justify a Terry stop. The decision emphasizes deference to law enforcement’s factual judgments when those judgments reflect an objectively reasonable understanding of statutory provisions. By upholding Mr. Nettles’s conviction, the Court has signaled that challenges to investigatory stops must focus on the unreasonableness of the officer’s perception, not on subsequent clarifications of the law.

Key takeaways include: the vitality of Heien in justifying investigatory stops, the necessity of a totality-of-circumstances analysis, and the ongoing balance between effective policing and Fourth Amendment safeguards.