Michigan Supreme Court Bars Automatic Death-in-Prison Sentences for Youngest Adults

04.18.25

The Michigan Supreme Court ruled last week that a mandatory sentence of life imprisonment without parole for young adults who were 19 or 20 years old at the time of the offense is a “grossly disproportionate punishment” that violates the Michigan Constitution.

The decision extends to 19- and 20-year-olds the court’s 2022 ruling in People v. Parks, which applied the federal constitutional ban on automatic life-without-parole sentences for juveniles to 18-year-olds under the broader and more protective provisions of the Michigan Constitution.

The Parks court found that late adolescent “brains are far more similar to juvenile brains . . . than to the brains of fully matured adults.” Like juveniles, late adolescents are more “susceptible to negative outside influences, including peer pressure,” and tend “to give less consideration to the costs or consequences of a decision.”

Like those of younger children, late adolescents’ brains “transform as they age, allowing them to reform into persons who are more likely to be capable of making more thoughtful and rational decisions.” The court found that “18-year-olds, much like their juvenile counterparts, are generally capable of significant change” and rehabilitation.

As a result, the Parks court held that the state’s individualized sentencing procedure for juveniles applies to 18-year-olds:

Because of the dynamic neurological changes that late adolescents undergo as their brains develop over time and essentially rewire themselves, automatic condemnation to die in prison at 18 is beyond severity—it is cruelty.

Last week’s decision came in the combined cases of Andrew Czarnecki and Montario Taylor, who were convicted of first-degree murder and sentenced to mandatory life in prison without parole for offenses when they 19 and 20 years old, respectively. They argued on appeal that Parks should be extended to 19- and 20-year-olds.

Based on the “unrebutted scientific consensus” before it, the Michigan Supreme Court found that 19- and 20-year-olds share with 18-year-olds “the same mitigating characteristics of late-adolescent brain development” that distinguish children from adults for sentencing purposes and render automatic life-without-parole sentences disproportionate.

“[A]s a class, 19- and 20-year-old late adolescents are more similar to juveniles in neurological terms than they are to older adults,” the court found. “There has long been a scientific consensus that, in terms of neurological development, there is ‘no meaningful distinction’ between a 17-year-old and 18-year-old individual…But the lack of meaningful distinction does not stop at age 18.”

Indeed, the court observed, late adolescents’ capacity for rehabilitation is demonstrated by data showing that the likelihood of committing violent or property crimes decreases during a person’s twenties and continues to decline significantly as they age.

Michigan law further demonstrates society’s assessment that people between 18 and 21 “are mature enough to hold some but not all of the rights and privileges of full adulthood,” the court observed. People under 21 cannot serve as an elected state legislator in Michigan or run for U.S. Senate. And state laws protect them from “risky or potentially dangerous or addictive activities” by prohibiting under-21-year-olds from gambling, buying or using alcohol or cannabis, and obtaining a concealed pistol license.

The court concluded that the Michigan Constitution does not permit the imposition of the state’s harshest available punishment against 19- and 20-years-olds, who are “presumptively neurologically indistinguishable from either a teenage juvenile offender or an 18-year-old offender” and therefore must receive the same individualized sentencing procedure as juveniles.

“[A]s applied to defendants who were 19 or 20 years old at the time of their crime,” the court held, “a mandatory LWOP sentence that does not allow for consideration of the mitigating factors of youth or the potential for rehabilitation is a grossly disproportionate punishment” in violation of the state constitution.

The court held that this latest decision applies retroactively, allowing roughly 580 people serving sentences for first-degree murder committed when they were 19 or 20-years-old to request resentencing.

Michigan now joins Washington and Massachusetts in extending the prohibition against mandatory life-without-parole sentences to people under 21 years old, according to the Death Penalty Information Center.