Montgomery v. Louisiana
The Supreme Court ruled that when it announces a new constitutional rule taking a punishment completely off the table for a class of offenders, state courts reviewing old, already-final cases must apply that rule too — not just courts hearing fresh appeals.
The decision means Henry Montgomery, sentenced to automatic life without parole as a 17-year-old nearly fifty years earlier, and thousands of other juvenile offenders serving mandatory life sentences, must now get a chance to argue for parole eligibility under the Court's 2012 ruling in Miller v. Alabama.
“There is no grandfather clause that permits States to enforce punishments the Constitution forbids.”
The majority's core reasoning that finality cannot excuse an unconstitutional sentence.
How it got here: A Louisiana trial court and the Louisiana Supreme Court denied Montgomery's motion, ruling Miller did not apply retroactively to already-final cases; he sought review in the U.S. Supreme Court.
The Case in Depth
What happened
Henry Montgomery killed a deputy sheriff in Louisiana in 1963 when he was 17. Because his jury returned a verdict of "guilty without capital punishment," Louisiana law automatically imposed life without parole, with no chance for him to present evidence about his age or potential for rehabilitation. Decades later, the Supreme Court's 2012 decision in Miller v. Alabama held that mandatory life without parole for juvenile killers violates the Eighth Amendment, prompting Montgomery to seek relief.
The question before the Court
If the Supreme Court bans a certain punishment for a whole group of people, must state courts apply that ban to prisoners whose sentences were already final?
The Court's answer
Yes — the Constitution requires state courts hearing old, already-final cases to apply a new rule when that rule is "substantive," meaning it puts certain punishments or conduct entirely beyond the government's power to punish, rather than merely changing the procedure used to decide a sentence. The Court explained that once the Constitution says a punishment simply cannot be imposed on a group of people, any sentence imposing it is void, no matter how long ago it became final — finality cannot rescue an unconstitutional sentence.
Applying that principle, the Court held that its 2012 ruling in Miller v. Alabama — which found mandatory life without parole unconstitutional for nearly all juvenile offenders — is exactly this kind of substantive rule. So Louisiana's courts, which had refused to reconsider Montgomery's decades-old sentence, were wrong, and Montgomery and similarly situated prisoners must now get a chance to show their crimes reflected a childhood mistake rather than permanent incorrigibility.
Curious how the Court got there? See the step-by-step legal reasoning →
Why it matters
Hundreds of juvenile offenders across the country who received mandatory life-without-parole sentences before Miller was decided in 2012 can now seek parole consideration, even though their convictions became final decades ago. States do not have to hold new resentencing hearings — offering parole eligibility satisfies the ruling — but they can no longer treat those sentences as untouchable.
What changes now
Montgomery's case returns to Louisiana's courts, and he — along with juvenile offenders nationwide who received mandatory life-without-parole sentences before Miller — becomes eligible to seek parole consideration. States are not required to hold new sentencing hearings; simply offering parole eligibility satisfies the Constitution. The ruling is final and resolves the retroactivity question definitively, though implementation will vary state by state.
What this does not decide
The Court did not decide that any particular juvenile offender, including Montgomery, must be released or resentenced. It held only that states must give these prisoners a chance to show rehabilitation, typically through parole eligibility, not that mandatory life without parole itself must be replaced with new courtroom hearings.
Concurrences and dissents
Dissent — Justice Scalia
Justice Scalia argued the Court lacked jurisdiction at all, because Teague's retroactivity framework was always an interpretation of the federal habeas statute, not a constitutional command, so nothing required Louisiana's own courts to apply it. He also argued that even on the merits the majority was rewriting Miller, which explicitly said it did not categorically bar any punishment but only required a sentencing process — meaning Miller was procedural, not 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 relief on collateral review. He traced historical practice showing postconviction relief was always a matter of legislative grace, not constitutional command, and warned the majority's reasoning has no logical stopping point.
How the Court got there
The legal reasoning, step by step
- The Court first had to decide whether it even had power to review this case, since Louisiana argued that state postconviction procedures are a matter of state law beyond federal review. It concluded that if the Constitution itself requires a rule to be applied retroactively, a state court's refusal to do so raises a federal question the Supreme Court can review.
- The Court then distinguished 'substantive' constitutional rules — which flatly forbid punishing certain conduct or punishing a certain group of people a certain way — from 'procedural' rules, which merely regulate how guilt or sentence is determined. Under this framework (drawn from the Teague v. Lane retroactivity doctrine), procedural errors can still leave a valid, lawful conviction in place, but a substantive rule means the punishment itself was never something the government had the power to impose.
- Because a substantive rule voids the government's power to punish outright, the Court reasoned that any sentence imposed in violation of such a rule is illegal from the start — not just an error to be overlooked once a case is final. It found this principle rooted in a long line of cases treating convictions under unconstitutional laws as void, not merely erroneous.
- The Court then reasoned that if a state may not keep a prisoner locked up in violation of a substantive constitutional rule when a federal court reviews the case, it cannot reach a different result simply because the review happens in its own state courts instead — the Supremacy Clause requires the same outcome either way.
- Turning to Miller v. Alabama itself, the Court concluded that Miller was substantive because it rendered life without parole unconstitutional for all but the rare juvenile whose crime reflects permanent incorrigibility, rather than merely requiring judges to follow a certain process before choosing a sentence.
- Having classified Miller as substantive, the Court held that its ban on mandatory juvenile life without parole must be applied retroactively in state collateral proceedings, meaning states can satisfy the ruling by making juvenile offenders eligible for parole rather than by holding full resentencing hearings.
Doctrinal impact
Cases affected by this decision
Reaffirms Teague v. Lane (489 U. S. 288)
The Court builds on Teague's framework, holding its substantive-rule exception rests on constitutional grounds binding on states.
Reaffirms Miller v. Alabama (567 U. S. ___)
The Court confirms Miller announced a substantive rule and must be applied to already-final cases.
Distinguishes Danforth v. Minnesota (552 U. S. 264)
The Court says Danforth never addressed whether states must retroactively apply substantive rules.