Montgomery v. Louisiana
The Court ruled that when it strikes down a whole category of punishment as unconstitutional, state courts reviewing old, already-final convictions must give that ruling retroactive effect — they can't simply say the case is too old to matter. That meant a man sentenced to automatic life without parole at 17, back in 1963, could now seek a chance at parole.
The decision resolves a long-simmering dispute over how far a landmark 2012 ruling banning mandatory juvenile life-without-parole sentences reaches, and it puts thousands of similarly sentenced prisoners around the country back in front of courts to seek release or parole consideration.
“There is no grandfather clause that permits States to enforce punishments the Constitution forbids.”
The majority's answer to the argument that finality should shield old sentences from constitutional attack.
How it got here: Montgomery asked a Louisiana trial court to correct his sentence as illegal under Miller; the court refused, the Louisiana Supreme Court denied review, and Montgomery asked the U.S. Supreme Court to step in.
The Case in Depth
What happened
Henry Montgomery killed a deputy sheriff in Louisiana in 1963 when he was 17. A jury verdict automatically triggered a sentence of life without parole, so he never had a chance to present evidence about his youth or potential for change. Nearly 50 years later, the Supreme Court ruled in a different case that mandatory life without parole for juvenile killers is unconstitutional, and Montgomery argued that ruling should free him to seek parole too.
The question before the Court
When someone was sentenced as a teenager decades ago to automatic life without parole, does the Constitution require state courts to apply the Supreme Court's later ban on that kind of sentence to his old, final case?
The Court's answer
Yes — the Constitution requires state courts, when reviewing old and already-final convictions, to apply a later Supreme Court ruling that removes a punishment from a government's power entirely (a "substantive rule"). Because the Court's 2012 decision in Miller v. Alabama banned mandatory life without parole for all but the rarest juvenile killers, it counts as substantive, not merely procedural, and Louisiana's courts could not refuse to apply it to Montgomery's decades-old sentence just because his case was long final.
The Court added an important limit on the remedy: states do not need to hold brand-new sentencing hearings for every affected prisoner. Simply making juvenile offenders like Montgomery eligible for parole consideration is enough to satisfy the Constitution, since that gives them a chance to show they are not among the rare offenders whose crimes reflect permanent incorrigibility.
Curious how the Court got there? See the step-by-step legal reasoning →
Why it matters
Prisoners across the country who were automatically sentenced to life without parole as juveniles — many of them now decades into their sentences — gained a path to seek parole hearings, even though their convictions became final long before the Court's 2012 ruling. States were told they don't have to hold new sentencing hearings; offering parole eligibility is enough to satisfy the Constitution.
What changes now
The Louisiana Supreme Court's decision is reversed, and Montgomery's case goes back for further proceedings consistent with the ruling. Louisiana and other states with similarly sentenced prisoners now must provide some mechanism — such as parole eligibility — for juvenile offenders serving mandatory life-without-parole sentences to show they do not fall within the narrow class for whom that punishment remains constitutional. This is a final merits ruling, not a temporary order.
What this does not decide
The Court's holding is limited to Teague's substantive-rule exception; it expressly leaves open whether the Constitution also requires states to retroactively apply new "watershed" procedural rules, the framework's other exception. It also does not require states to hold new sentencing hearings, only some mechanism for parole consideration.
Concurrences and dissents
Dissent — Justice Scalia
“The Court has no jurisdiction to decide this case, and the decision it arrives at is wrong.”Scalia's opening statement rejecting both the majority's jurisdictional theory and its merits holding.
Justice Scalia argued the Court had no jurisdiction at all, because Teague's retroactivity framework was always understood as an interpretation of the federal habeas statute, not a constitutional command, so it cannot bind state courts. He also argued that even if jurisdiction existed, Miller's own text said it did not categorically ban any punishment, only required a sentencing process, so the majority was rewriting Miller to make it substantive.
Dissent — Justice Thomas
Justice Thomas joined Scalia's dissent but wrote separately to argue that no provision of the Constitution — not the Supremacy Clause, Article III, Due Process, or Equal Protection — supports a right to retroactive remedies on collateral review. He traced historical practice showing postconviction relief was always a matter of legislative grace, not constitutional entitlement.
How the Court got there
The legal reasoning, step by step
- The Court first asked whether it even had authority to review the case, since Louisiana argued its own courts were free to define the scope of relief in their own collateral proceedings — a state-law question beyond federal review. The Court held that if the Constitution itself requires a rule to be applied retroactively, a state court's refusal to do so is reviewable.
- The Court built on a framework from Teague v. Lane (a 1989 case describing when new constitutional rules apply to already-final convictions) that separates procedural rules, which govern how a trial is conducted, from substantive rules, which remove certain conduct or punishments entirely from a government's power to impose.
- The Court reasoned that because a substantive rule makes a conviction or sentence unlawful from the start, no legitimate reason exists to leave it in place merely because the case is already final — unlike a procedural error, which doesn't necessarily mean the outcome was wrong.
- Extending that logic beyond federal habeas cases, the Court held that the Constitution's supremacy over state law requires state collateral-review courts, too, to give retroactive effect to new substantive rules whenever their proceedings are open to considering such claims.
- Applying that framework, the Court concluded that Miller v. Alabama's ban on mandatory life without parole for juvenile killers is a substantive rule, because it takes that punishment off the table for all but the rare juvenile whose crime shows permanent incorrigibility.
- Because Miller is substantive, the Court held it must be applied retroactively, though it clarified that states can satisfy this by offering juvenile offenders a chance at parole rather than holding entirely new sentencing hearings.
Doctrinal impact
Cases affected by this decision
Reaffirms Teague v. Lane (489 U. S. 288)
The Court relies on and constitutionalizes Teague's rule that new substantive constitutional rules must be applied retroactively.
Distinguishes Danforth v. Minnesota (552 U. S. 264)
The Court says Danforth never addressed whether states must retroactively apply Teague's substantive-rule exception.
Reaffirms Penry v. Lynaugh (492 U. S. 302)
The Court relies on Penry's definition of substantive rules as covering punishment bans tied to an offender's status.