Does the Sixth Amendment require that the individualized sentencing proceeding necessary to impose a life-without-parole sentence upon a juvenile homicide offender be a trial by jury?

QUESTION PRESENTED In Miller v. Alabama, 567 U.S. 460 (2012), this Court “h[e]ld that mandatory life without parole for those under the age of 18 at the time of their crimes violates the Eighth Amendment’s prohibition on ‘cruel and unusual punishments.’” Id. at 465. Instead, to comport with established principles of proportionality, “a judge or jury must have the opportunity to consider mitigating circumstances before imposing the harshest possible penalty for juveniles.” Id. at 489. This Court later recognized “[t]hat Miller did not impose a formal factfinding requirement... .” Montgomery uv. Louisiana, 136 S.Ct. 718, 735 (2016). Nevertheless, the Oklahoma Court of Criminal Appeals concluded—in direct conflict with three other state supreme courts—that the Sixth Amendment requires that a jury find beyond a reasonable doubt that a juvenile homicide offender is irreparably corrupt and permanently incorrigible before a sentence of life without parole may be imposed under Miller. The question presented is: Does the Sixth Amendment require that the individualized sentencing proceeding necessary to impose a life-without-parole sentence upon a juvenile homicide offender be a trial by jury?