The Supreme Court has taken a serious step in the fight against mass incarceration on Monday. In the case, Montgomery v. Louisiana, the Court ruled that those sentenced to automatic life without the possibility of parole as minors can petition for early release. This holding gives retroactive effect to the 2012 case, Miller v. Alabama, which held that states could not give juveniles mandatory minimum sentences of life without parole.

Henry Montgomery, the petitioner in this case, was in prison for 46 years for a crime he committed when he was 17 years old. Justice Kennedy, writing for the majority of the Court observed, “prisoners like Montgomery must be given the opportunity to show their crime did not reflect irreparable corruption; and, if it did not, their hope for some years of life outside prison walls must be restored.”

Montgomery’s case will now be sent back to the state courts in Louisiana. Montgomery was sentenced in the murder of a Sheriff’s deputy in 1963.