Juvenile Forensics & Adolescent Decision-Making

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Michigan’s Ruling That Redefines Youth & Justice

In April 2025, the Michigan Supreme Court made a groundbreaking decision. The court held that mandatory life-without-parole sentences for 19- and 20-year-olds convicted of murder violate the state constitution. The justices concluded that imposing such punishment without considering an offender’s youth and capacity for change is “grossly disproportionate.” This ruling is significant. The court relied on scientific evidence showing that brain development continues into the early twenties. It recognizes late adolescence as a distinct developmental stage.

The Importance of Neuroscience in Sentencing

This ruling sets an important precedent. Neuroscience research on adolescent development can influence sentencing decisions beyond the federal juvenile cutoff of 18. By extending constitutional protections to late adolescents, the decision illustrates how courts are increasingly turning to developmental science to shape criminal sentencing. This shift is crucial for ensuring that the justice system recognizes the unique circumstances of young adults.

Late Adolescence, Neuroscience, and Sentencing Disparities

While landmark U.S. Supreme Court decisions prohibit extreme punishments, such as mandatory life without parole for juveniles under 18, many legal systems still treat 18-, 19-, and 20-year-olds as fully mature adults. This persists despite extensive research showing that decision-making, impulse control, and risk assessment in these “emerging adults” often resemble those of younger adolescents.

Until recent state court rulings, including Michigan’s, individuals in this age group routinely faced the same mandatory adult penalties as older offenders. This was true even with a growing body of developmental science advocating for a more nuanced approach. Even when life-without-parole sentences are avoided, people who committed offenses in their teens or early adulthood frequently receive disproportionately severe punishments.

Disparities in Sentencing

Youth of color are especially likely to be transferred to adult courts and subjected to harsher sentencing. The result is an enduring tension between retributive justice—punishment driven primarily by the severity of the offense—and developmentally informed justice, which accounts for maturity, culpability, and capacity for rehabilitation.

Public fear of crime and tough-on-crime politics often exacerbate this divide. They encourage lawmakers to sideline adolescent neuroscience, further widening the gap between science and sentencing.

The Path Forward

As we move forward, it’s essential to integrate developmental science into the legal framework. This integration can help ensure that young adults are treated fairly and justly. It’s not just about punishment; it’s about understanding the individual’s potential for change.

Conclusion

The Michigan Supreme Court's ruling is a significant step toward a more equitable justice system. By recognizing the developmental differences in late adolescents, we can foster a legal environment that prioritizes rehabilitation over retribution. This is not just a legal issue; it’s a moral imperative. We must strive for a justice system that reflects our understanding of human development and the capacity for growth.

References:

Fair and Just Prosecution. (2024, December 23). FJP urges MI Supreme Court to find mandatory life without parole sentences for emerging adults unconstitutional. https://fairandjustprosecution.org/press-releases/fjp-urges-mi-supreme-court-to-find-mandatory-life-without-parole-sentences-for-emerging-adults-unconstitutional/

National Conference of State Legislatures. (2025, June 30). Juvenile justice update | June 2025. https://www.ncsl.org/newsletter/details/juvenile-justice-update-june-2025

Poggio, M. (2025, June 27). How states are rethinking life without parole for youth. Law360. https://www.law360.com/articles/2330522/how-states-are-rethinking-life-without-parole-for-youth

Zhao, R. (2022, April). Second chances: Why Michigan should categorically prohibit the sentence of juvenile life without parole. Michigan Journal of Law Reform. https://mjlr.org/journal/second-chances-why-michigan-should-categorically-prohibit-the-sentence-of-juvenile-life-without-parole/