In 2012 in Miller v. Alabama the Supreme Court ruled 5-4 that states may not mandate that juvenile offenders be sentenced to life in prison without the possibility of parole. In Montgomery v. Louisiana the Court will decide whether Miller is retroactive; that is, whether it should apply to those convicted before the case was decided.
This case will be decided next term (by the end of June 2016). The Court agreed to hear a case raising the exact same issue, also from Louisiana, this term. Toca v. Louisiana was dismissed when George Toca was released from prison after pleading guilty to two counts of armed robbery in exchange for his murder conviction being vacated.