The Supreme Court opened its new term Monday pondering whether a police officer's misunderstanding of the law can justify a traffic stop that led to the seizure of illegal drugs.

Several of the justices questioned whether it was reasonable for the North Carolina officer to pull over a car because one of its two brake lights was burned out, even though a quirky state law requires only one light to be functional, the Associated Press reports.

Monday's argument on the police action involves an appeal by Nicholas Heien, whose Ford Escort was pulled over when an officer saw that the right rear brake light wasn't working. The officer found cocaine during an ensuing search, and Heien was later convicted of drug trafficking.

The case tests whether the officer's mistaken understanding of the law makes the traffic stop unreasonable and the search a violation of Heien's constitutional rights. A divided state Supreme Court said the mistake was reasonable enough to justify the routine traffic stop and refused to toss out the drug evidence.

A decision in the case of Heien v. North Carolina, 14-604, should come by late spring.