In light of a U.S. Supreme Court decision declaring the law was too vague as to what constitutes a violent career criminal, a convicted murderer’s mandatory 15-year sentence on a gun charge will have to be re-examined, a federal appeals court ruled.

On Monday, the U.S. Court of Appeals for the Third Circuit held that Ronnie Peppers may have been wrongly sentenced to the mandatory minimum of 15 years in prison for being a felon in possession of a firearm under the Armed Career Criminal Act.