The Supreme Court of the United States has agreed to hear arguments on the constitutionality of traffic stops based on a police officer’s mistaken understanding of the law under the Fourth Amendment. The case, Heien v. North Carolina, stems from the drug trafficking prosecution of the defendant-petitioner, which resulted from a discovery of cocaine during the search of a car pulled over for a burnt brake light.

The Traffic Stop

The defendant-petitioner, Mr. Heien, was a passenger in his own vehicle as it was operated by a friend down an interstate highway in North Carolina. A highway patrol officer observed the defendant’s friend operating the vehicle with a stiff and nervous expression, “gripping the steering wheel at a 10 and 2 position, looking straight ahead.” The officer followed the vehicle until he noticed that only one of the two brake lights were functioning. While the state statute only requires that vehicles have only one functioning break light, the officer interpreted the statute incorrectly and issued a warning to the defendant, who was the vehicle’s owner. The officers then asked the defendant if he could search the vehicle, and the defendant consented. After a forty minute search of the vehicle, the officer discovered a plastic sandwich bag containing cocaine. The defendant was charged and convicted on the charge of trafficking cocaine.

The Issues in Dispute

The defendant in this case argued that the initial traffic stop violated his Fourth Amendment right against unreasonable searches and seizures because the stop was based on a mistake of law on account of the officer. The law on the validity of traffic stops is pretty well established – an officer may not conduct a traffic stop (or temporarily seize the vehicle) unless the officer reasonably suspects that a traffic law was violated, or that a crime has or is about to be committed. The law does not expect the officer to be completely correct in his suspicions each time; there will certainly be times where the officer makes observations that he believes, based on his experiences, suggest that criminal activity is afoot, but where in reality there was just a mistake of fact – no crime, just seemingly suspicious behavior. The officer must only have a reasonable basis for the suspicion as recognized by law, even though the officer may sometimes be mistaken.

The issue in this case, however, is not that the officer mistakenly believed that the defendant’s had a burnt brake light. That would constitute a mistake of fact, which courts usually excuse. Instead, the challenge raised by the defendant was that the officer mistakenly believed that a single non-functional brake light constituted a violation of the state statute requiring vehicles to be equipped with “a stop light.” The latter issue is a mistake of law – where the officer misinterprets the law and applies this misinterpretation to the driver.

A Criminal Defense Attorney’s Thoughts

Two different aspects of this case make it especially striking. The first concerns the initial basis on which the officer suspected and followed the vehicle. In this case, the officer began to follow the vehicle after observing the driver’s stiff demeanor, holding the steering tightly at 10 and 2, and looking straight ahead. In other words, the fact that the driver’s behavior completely conformed to state driving laws served as the basis of the officer’s reasonable suspicion to follow, and subsequently stop, the vehicle. While the officer’s suspicion may seem understandable in practical terms, it was nonetheless illogical. Here, the vehicle was initially suspected and followed because the driver of the vehicle was in seemingly full and perfect adherence with safe driving practices – holding the steering wheel at 10 and 2 and focusing on the road ahead.

The second striking aspect of this case is the reasoning on which the courts of North Carolina premised their decisions to uphold the trial judge’s denial of the defendant’s motion to suppress. The North Carolina Supreme Court in this case stated that “so long as an officer’s mistake is reasonable, it may give rise to reasonable suspicion” for purposes of infringing on the driver’s Fourth Amendment freedom from police seizures. Almost half of the North Carolina Supreme Court justices, however, picked up on the flaw in this reasoning and dissented. The dissenting justices recognized that it would be unjust to require citizens to know the law or face punishment, while at the same time excusing law enforcement officers from that same requirement. If citizens are generally held culpable for acts that constitute crimes, despite their lack of knowledge that an act was criminal, it is only fair to require officers charged with enforcing the laws to have a good understanding of the laws so that enforcement is effected in a fair and predictable manner. By excusing officers from infringing on a citizens constitutional rights based on a misunderstanding of the law they are charged with enforcing, the courts effectively shield officers at the expense of the citizenry’s constitutionally protected rights.

The Supreme Court will be hearing arguments from both the defendant and the State of North Carolina on October 6, 2014. The Court has also granted permission to the U.S. Solicitor General to argue why the Supreme Court should not hold that a police officer’s reasonable mistake of law cannot support reasonable suspicion. The Court is expected to issue a decision months after arguments are heard.