An Officer’s Objectively Reasonable Mistake of Law Can Support Finding of Probable Cause

Overview: The U.S. Supreme Court held that an officer’s mistaken belief that a driver had violated a state vehicle code regarding operability of brake lights, even if the driver was in compliance with the law, provided sufficient cause for the officer to make a traffic stop. The Court held the stop satisfied the requirements of probable cause and was therefore reasonable and valid.

Training Points: In its opinion, the Court reiterated, “this Court’s holding does not discourage officers from learning the law.” As such, officers should continue to stay-up-to-date on relevant statutes and case law to ensure they have sufficient cause to initiate stops and effectuate arrests. Officers must remember that only “objectively reasonable” mistakes may be upheld by a court. A “reasonable” mistake of law justifies an investigatory stop, but if the court finds the mistake was “unreasonable,” the stop, detention, arrest and any fruits of the crime may be suppressed. Officers should continue to fully document their reports and provide all necessary background and training regarding the laws upon which they are initiating an investigatory/traffic stop.

Summary Analysis: In Heien v. North Carolina, an officer initiated a traffic stop on a vehicle that had one brake light working in violation of the State’s vehicle code. During the traffic stop, the officer became suspicious of two of the vehicle’s occupants. During a consent search of the vehicle, the officer found cocaine. Defendant Heien was charged with attempted trafficking. At trial, Heien filed a motion to suppress. The trial court denied the motion because the court found the faulty brake light gave the officer reasonable suspicion to initiate the traffic stop. The North Carolina Court of Appeals reversed, holding that the relevant code provision that requires a car to be equipped with a stop lamp requires only a single stop lamp, which Heien’s vehicle had. Therefore, the appeal court found, the justification for the stop was objectively unreasonable.

Reversing, the Supreme Court held that the officer’s mistaken understanding of the law, even if no violation of state law occurred, was reasonable. The court found that the officer’s error was reasonable because the State’s vehicle code requiring “a stop lamp” also provides that the lamp “may be incorporated into a unit with one or more other rear lamps” and that “all originally equipped rear lamps” must be “in good working order.” Although the state court held the “rear lamps” do not include the brake lamps, the word “other,” coupled with the lack of state court precedent interpreting this statute, made it objectively reasonable for the officer to think a faulty brake light constituted a violation. As such, the Court held the stop was valid.