U.S. Supreme Court · 2016

Montgomery v. Louisiana

577 U.S. 190 (2016)

Holding

Held that Miller v. Alabama announced a substantive rule of constitutional law that applies retroactively on state collateral review. The Court characterized Miller as rendering life without parole unconstitutional for "a class of defendants because of their status" -- juvenile offenders "whose crimes reflect the transient immaturity of youth" -- as opposed to "the rare juvenile offender whose crime reflects irreparable corruption."

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Claims this case relied on

Adolescent personality and character are still forming and are not reliable indicators of fixed adult character; most adolescents who engage in antisocial behavior, including serious offending, desist as they mature, so adolescent conduct is a poor predictor of irretrievable depravity.
Evidence strength: HighScientific consensus: Established· adolescent personality development / desistance

Claims relevant to this case

Adolescents have a diminished capacity for self-regulation and impulse control relative to adults; the neural systems supporting cognitive control and behavioral inhibition mature gradually across adolescence and do not reach adult levels until the late teens to early twenties.
Evidence strength: HighScientific consensus: Established· adolescent self-regulation / impulse control
Structured, developmentally-appropriate interventions can, on average, reduce reoffending among juveniles; as a group, adolescents are responsive to rehabilitation -- though effects are modest and depend strongly on the type of program, the targeting of higher-risk youth, and the quality of implementation.
Evidence strength: ModerateScientific consensus: Established· juvenile rehabilitation / intervention effectiveness