In Montgomery v. Louisiana the United States Supreme Court ruled that their 2012 decision in Miller v. Alabama, barring mandatory life without parole sentences for youth, applies retroactively. The decision means that 69-year-old Henry Montgomery, along with the others serving similar mandatory life without parole sentences, will receive new sentencing hearings or be considered for parole.
Justice Kennedy wrote that "there is no grandfather clause that permits states to enforce punishments the Constitution forbids." He continued that Miller is no less substantive than Roper and Graham, and said that "After Miller, it will be the rare juvenile offender who can receive that same sentence. The only difference between Roper and Graham, on the one hand, and Miller, on the other hand, is that Miller drew a line between children whose crimes reflect transient immaturity and those rare children whose crimes reflect irreparable corruption. The fact that life without parole could be a proportionate sentence for the latter kind of juvenile offender does not mean that all other children imprisoned under a disproportionate sentence have not suffered the deprivation of a substantive right."