MI HB4506

Establishes sentencing guidelines for defendants aged 18-21 at the time of their offense who are convicted of specific serious crimes including first-degree murder, terrorism, and explosives violations

Allows prosecutors to file a motion seeking life without parole for eligible defendants, with a 42-day deadline after conviction for new cases or 360 days after the act's effective date for prior convictions

Requires courts to hold a sentencing hearing considering factors from Miller v Alabama (2012), including the defendant's incarceration record, and to specify aggravating and mitigating circumstances on the record

If life without parole is not imposed, mandates a minimum sentence of 35-50 years with a maximum of at least 80 years, to be served consecutively to related sentences

Establishes resentencing priority giving precedence to defendants who have already served 25+ years, and requires credit for time already served