Heien v. North Carolina


Can a police officer’s misinterpretation of the law provide the reasonable suspicion necessary to justify a traffic stop? 

On April 29, 2009, Sergeant Matt Darisse arrested Nicholas Heien in North Carolina after a traffic stop that Darisse initiated based on his misinterpretation of relevant state statutes. When Heien tried to exclude evidence that resulted from the traffic stop during his subsequent trial, the trial court denied his request. The North Carolina Court of Appeals reversed the trial court’s decision, holding that an officer cannot justify a traffic stop when a mistake of law serves as the primary justification for the stop. In December 2012, the North Carolina Supreme Court overturned the appellate court’s ruling. The Supreme Court of the United States will now consider whether a police officer’s mistake of law can serve as the requisite reasonable suspicion needed for a constitutional traffic stop. Heien argues that allowing police officers to base traffic stops on misinterpretations of the law would violate the Fourth Amendment rights of those stopped. North Carolina, however asserts that just as police officers can execute constitutional traffic stops by relying on reasonable mistakes of fact, a police officer can justify a stop if it is based on a reasonable but mistaken interpretation of a statute. The Court’s ruling implicates the Fourth Amendment practices of law enforcement, the right to privacy of individuals, and the right of individuals to be free from restraint. 

Questions as Framed for the Court by the Parties 

Whether a police officer’s mistake of law can provide the individualized suspicion that the Fourth Amendment requires to justify a traffic stop.

On April 29, 2009, Sergeant Matt Darisse of the Surry County Sheriff’s Department in North Carolina pulled over a vehicle in which Nicholas Heien was a passenger. See State v. Heien, 737 S.E.2d 351, 352 (N.C. 2012). Darisse initiated the stop because one of the rear brake lights on the vehicle was not working properly.

Edited by 


The authors would like to thank Professor Sherry Colb of Cornell Law School for her help and for directing them to her work on Heien v. North Carolina

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unreasonable search and seizure

A search and seizure by a law enforcement officer without a search warrant and without probable cause to believe that evidence of a crime is present. Such a search or seizure is unconstitutional under the Fourth Amendment (applied to the states by the Fourteenth Amendment), and evidence obtained from the unlawful search may not be introduced in court. (See also: fruit of the poisonous tree)

Reasonable Suspicion


Reasonable suspicion is a standard used in criminal procedure. Reasonable suspicion is used in determining the legality of a police officer's decision to perform a search.

Qualified immunity


Qualified immunity is a type of legal immunity. Qualified immunity “Qualified immunity balances two important interests—the need to hold public officials accountable when they exercise power irresponsibly and the need to shield officials from harassment, distraction, and liability when they perform their duties reasonably.” Pearson v. Callahan .