Learn how a series of Supreme Court decisions has impacted juvenile murder convictions on the national and state level in these videos excerpted from Second Chance Kids | FRONTLINE. Citing improved scientific understanding of the teenage brain, the Supreme Court ruled three times in cases involving violent juvenile offenders: on banning the execution of juveniles (2005), limiting life without parole sentences (2010), and abolishing mandatory life sentences without the possibility of parole (2012). Because states differed widely in their interpretation of its decisions, the Supreme Court ruled again in 2016, forcing states that had resisted the 2012 decision to act and commute life sentences.