Montgomery v. Louisiana
The Supreme Court ruled that its earlier decision banning mandatory life-without-parole sentences for juvenile killers must be applied retroactively, meaning people sentenced decades ago under that now-unconstitutional rule can seek new consideration.
The decision means states cannot simply treat old juvenile life sentences as untouchable just because the convictions became final years before the Court changed the law, giving people like Henry Montgomery, sentenced at 17 in 1963, a chance to argue for parole eligibility.
“There is no grandfather clause that permits States to enforce punishments the Constitution forbids.”
Explaining why old juvenile life sentences cannot be shielded just because they are already final.
How it got here: A Louisiana trial court and the Louisiana Supreme Court denied Montgomery's motion to correct his sentence, ruling Miller was not retroactive; the U.S. Supreme Court agreed to review.
The Case in Depth
What happened
Henry Montgomery killed a deputy sheriff in Louisiana in 1963 at age 17 and received a mandatory sentence of life without parole, with no chance to present evidence about his youth or potential for change. Decades later, the Supreme Court ruled in Miller v. Alabama that mandatory life without parole for juvenile killers violates the Eighth Amendment. Montgomery sought to have his old sentence corrected under Miller, but Louisiana courts said Miller did not apply to already-final cases like his.
The question before the Court
If the Supreme Court bans a type of punishment for juveniles, must people already serving that sentence for decades get a chance at a new outcome?
The Court's answer
Yes — the Court ruled that when it announces a new substantive constitutional rule (one that puts a punishment entirely off-limits for a category of people, rather than just changing procedures), state courts must give that rule retroactive effect, even for prisoners whose convictions became final years or decades earlier. The Court reasoned that leaving an unconstitutional sentence in place would mean the government keeps enforcing a punishment the Constitution simply forbids.
Applying that principle, the Court found that Miller v. Alabama's rule against mandatory life without parole for juvenile killers was substantive, not merely procedural, because it effectively barred that sentence for all but the rarest juvenile offenders. States do not have to hold full resentencing hearings, though — offering juvenile lifers a chance at parole is enough to satisfy the Constitution.
Curious how the Court got there? See the step-by-step legal reasoning →
Why it matters
Hundreds of people across the country who were sentenced to mandatory life without parole as juveniles, many decades ago, can now seek parole hearings or resentencing. States do not have to hold new full sentencing trials — they can simply make these prisoners eligible for parole — but they can no longer treat these old sentences as permanently locked in.
What changes now
The case is sent back to Louisiana, where Montgomery and similarly situated prisoners can seek parole eligibility or other remedies for their now-unconstitutional mandatory life sentences. States are not required to hold full resentencing hearings — offering parole consideration satisfies the Constitution. This is a final merits ruling, not a temporary order, and it will require states with juvenile mandatory life sentences to create mechanisms for reviewing those old cases.
What this does not decide
The Court did not decide that any specific prisoner, including Montgomery, must be released or resentenced — only that they must be given some opportunity, such as parole eligibility, to show their crime did not reflect permanent incorrigibility. The ruling also does not resolve whether Teague's separate exception for "watershed" procedural rules is constitutionally required.
Concurrences and dissents
Dissent — Justice Scalia
Justice Scalia argued the Court lacked jurisdiction because states are free to decide, as a matter of state law, whether to give new constitutional rules retroactive effect in their own collateral proceedings, and nothing in the Constitution requires otherwise. He also argued that even accepting jurisdiction, Miller expressly said it did not categorically bar any punishment, so the majority was rewriting Miller into a substantive rule it never claimed to be.
Dissent — Justice Thomas
Justice Thomas joined Scalia's dissent and 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 the history of habeas relief to show postconviction relief has always been a matter of legislative grace, not constitutional command.
How the Court got there
The legal reasoning, step by step
- The Court distinguished between procedural rules, which only regulate how guilt or sentences are determined, and substantive rules, which place certain punishments or conduct entirely beyond a government's power to impose — a category the Court's earlier Teague v. Lane decision said must always apply retroactively.
- The Court reasoned that because a substantive rule makes a punishment illegal outright, leaving a conviction or sentence in place under that punishment would mean enforcing something the Constitution simply forbids, unlike a procedural error, which might still have led to an accurate result.
- Relying on the Constitution's Supremacy Clause, which makes federal constitutional rules binding on state courts, the Court held that once a state opens its collateral-review process to a category of claim, it cannot refuse to give effect to a substantive federal constitutional rule within that process.
- Turning to Miller itself, the Court found that its ban on mandatory life without parole for children was not merely a procedural requirement to consider youth, but effectively barred that punishment for all but the rare juvenile whose crime reflects permanent incorrigibility — making it a substantive rule about who can be punished, not just how.
- Because Miller announced a substantive rule, the Court concluded it must be applied retroactively in state collateral proceedings, and states could satisfy this requirement short of full resentencing by simply making juvenile offenders eligible for parole consideration.
Doctrinal impact
Cases affected by this decision
Reaffirms Teague v. Lane (489 U.S. 288)
The Court relies on and extends Teague's rule that substantive constitutional rules must be applied retroactively.
Limits Miller v. Alabama
The Court reinterprets Miller as a substantive rule barring life without parole for most juveniles, not just a procedural requirement.