The United States Supreme Court ruled in Heien v. North Carolina that a police officer’s misunderstanding of the law does not make a traffic stop illegal. In this case, the police officer pulled the defendant over for a broken brake light. The officer then found cocaine in the car.
It turns out that the officer was mistaken in his interpretation of North Carolina’s law, which only requires one working brake light. However, the Supreme Court ruled that as long as an officer acts reasonably, a traffic stop is justified. The Court found that the officer’s mistake was reasonable, and therefore the traffic stop was legal.