In the seminal case of Commonwealth v. Mattis (2024), the Massachusetts Supreme Judicial Court delivered a landmark decision pertaining to the sentencing of "emerging adults." The case involved Sheldon Mattis, who received a mandatory sentence of life without the possibility of parole for a murder committed at the age of 18. Mattis challenged the constitutionality of this sentence, arguing that it constituted cruel or unusual punishment. The Court agreed with Mattis, holding that sentencing individuals between the ages of 18 and 20 to life without parole violates the prohibition against cruel or unusual punishment enshrined in the Massachusetts Constitution. The Court's reasoning centered on contemporary research in neurological development, which demonstrates that this age group – termed "emerging adults" – experiences ongoing brain maturation. Consequently, the Court concluded that life sentences without the possibility of parole represent a disproportionate punishment for individuals in this developmental stage.

In a pivotal 2024 ruling, Commonwealth v. Mattis, the Massachusetts Supreme Judicial Court declared that sentencing individuals between the ages of 18 and 20 to life in prison without the possibility of parole violates the state constitution's ban on cruel and unusual punishment. The case centered on Sheldon Mattis, who received a mandatory life sentence without parole for a murder he committed at 18. The Court, referencing contemporary neuroscientific research on brain development, concluded that such sentences are inherently disproportionate when applied to this specific age group, often referred to as "emerging adults."

In a major case, Commonwealth v. Mattis (2024), the highest court in Massachusetts decided that giving someone 18-20 years old a life sentence without parole for murder is unconstitutional. Sheldon Mattis, who was given this sentence for a murder he committed at 18, argued that it was a cruel and unusual punishment, which is forbidden by the state's constitution. The court agreed with Mattis. They explained that new scientific discoveries about how the brain develops show that these sentences are too harsh for young adults, who are still maturing.

Sheldon Mattis was only 18 years old when he was found guilty of murder and given a sentence he could never appeal: life in prison without the possibility of parole. He challenged this sentence, arguing that it was a really harsh punishment, especially for someone who wasn't fully grown. The highest court in Massachusetts agreed with Mattis. They looked at scientific studies that show how teenagers' brains are still developing, especially between 18 and 20 years old. The court decided that giving people in this age group, which they called "emerging adults," such a serious sentence is too harsh a punishment and goes against the part of the Massachusetts Constitution that forbids cruel or unusual punishment.