Commonwealth v. Mattis




Supreme Judicial Court of Massachusetts

Citation and Year

224 N.E.3d 410 (Mass. 2024)

Constitutional Provision or State Statute

MASS. CONST. Pt. 1, Art. XXVI (“cruel or unusual punishments”)

Nature of Case

Sheldon Mattis was convicted of first degree murder and sentenced to a mandatory term of life without the possibility of parole for a crime committed when he was 18 years old. By the time this case reached the state’s high court, the U.S. Supreme Court had barred all mandatory LWOP sentences for anyone under age 18 and, under the state constitution, the Massachusetts Supreme Judicial Court had banned youth life without parole entirely, even when imposed as a matter of discretion. Mattis argued that because the same brain science and legal principles driving those decisions apply to “emerging adults” up to age 25, his mandatory LWOP sentence violated the state constitution.


The ban on “cruel or unusual” punishments in Massachusetts’ constitution prohibits all life without parole sentences for anyone under age 21. This was the first high court ruling in the country banning LWOP for emerging adults.


To assess the constitutionality of Mattis’s claim, the court applied the “evolving standards” or “categorical framework” to his life without parole sentence. This requires the court to decide whether the challenged punishment is consistent with Massachusetts’ contemporary standards of decency, and whether the punishment is proportionate to both the offense and to the offender, considering factors (such as youth) that show reduced culpability.

To assess state standards of decency, the court looked both inward and outward, considering the myriad ways in which Massachusetts treats young, emerging adults differently from fully-grown adults (for example, the state Department of Youth Services is authorized to maintain custody of young people up to age 21); the national trend toward reducing life without parole sentences, particularly for young people (including state constitutional rulings by other state supreme courts); and “international statutes and decisions,” including a 2020 United Kingdom statute that banned life without parole for offenders under age 21. The court also looked to consensus brain science showing that the reduced culpability and enhanced capacity for rehabilitation found in young people extends well into the mid-20s.

That same brain science also informed the court’s proportionality analysis, as requiring young people to die in prison is inconsistent with their reduced culpability and capacity to change. Finally, the court recognized that imposing life without parole, even as a discretionary matter, requires sentencing courts to decide on the front end what can only be known later: Has this particular person shown the growth and capacity for change necessary to safely re-enter society? At the time of sentencing, it is “not possible to demonstrate that a juvenile [or emerging adult] offender is ‘irretrievably depraved’” such that a LWOP sentence is warranted.

Ultimately, the court held, “life without parole for emerging adults violates art. 26. Our comprehensive review informs us that Supreme Court precedent, as well as our own, dictates that youthful characteristics must be considered in sentencing, that the brains of emerging adults are not fully developed and are more similar to those of juveniles than older adults, and that our contemporary standards of decency in the Commonwealth and elsewhere disfavor imposing the Commonwealth’s harshest sentence on this cohort.”