Commonwealth v. Mattis

Summary

The court held that imposing life imprisonment without parole on offenders who were eighteen, nineteen, or twenty when they committed first-degree murder violates art. 26 of the Massachusetts Declaration of Rights. Relying on contemporary standards of decency, scientific evidence concerning emerging-adult development, and legislative distinctions between emerging adults and older adults, the court extended the constitutional protection previously afforded to juveniles. The court invalidated the statutory denial of parole for this age group and remanded for resentencing under the applicable statutory scheme.