CNN  — 

More than two years after Michigan’s deadliest school shooting, a judge imposed a historic sentence – and the harshest possible penalty – for the teenage gunman.

Oakland County Circuit Court Judge Kwamé Rowe sentenced Ethan Crumbley, 17, on Friday to life in prison without the possibility of parole for the November 2021 shooting that left four students dead at Oxford High School. Six other students and a teacher were also wounded in the attack.

It’s a punishment that has become both rare and a point of contention over concerns about sentencing a minor to die in a cell before they reach full maturity.

Crumbley, who was 15 at the time of the shooting, became the first minor to receive an original sentence of life without the possibility of parole in more than a decade since the US Supreme Court in 2012 banned mandatory life sentences for juveniles and ruled courts should consider the circumstances of each defendant and their maturity before such punishments are handed down.

Before issuing his sentence, Rowe told families of the victims who appeared in court that he knew “whatever sentence the court imposes will not bring your loved ones back or cure the mental anguish or the lifelong physical scars that some of you have, but I hope the sentence does allow you to close one chapter in your life.”

The judge dismissed last-minute pleas by Crumbley’s attorney who stated the teen’s life was salvageable. Rowe noted the “defendant in his own words” told the court, “This is nobody’s fault but his own.”

Judge considered likelihood of rehabilitation

Rowe, who was appointed to the 6th Circuit Court of Oakland County in 2021 by Michigan Gov. Gretchen Whitmer, made history after becoming the second Black man to serve on the Sixth Circuit bench, according to the county website.

In September, Rowe made headlines following his ruling that Crumbley would be eligible for life in prison without the possibility of parole.

Rowe considered the teen’s behavior both before the mass shooting and during his time in custody, he said.

“It’s clear to this court the defendant had an obsession with violence before the shooting,” Rowe said, citing Crumbley’s disturbing writings and documented violence against animals before the attack. Rowe said Crumbley’s rehabilitation in prison is unlikely because of his “obsession” with violence.

Shooter’s sentence came as state considers banning such punishments for minors

In a 2012 ruling, the US Supreme Court deemed it unconstitutional to sentence minors to mandatory life without the possibility of parole. The high court heard arguments urging them not to “give up” on child offenders who are still a work in progress, emotionally and developmentally, as one attorney called it.

Ethan Crumbly is escorted by sheriff deputies after being sentenced, Friday, Dec. 8, 2023, in Pontiac, Mich. Crumbly sentenced to life in prison for killing four students, wounding more and terrorizing Michigan's Oxford High School in 2021. A judge Friday rejected pleas for a shorter sentence and ensured that Crumbley, 17, will not get an opportunity for parole. (AP Photo/Carlos Osorio)

Justice Elena Kagan said in the court’s opinion it would be wrong for states to ignore the chance that these now-adult inmates may someday be rehabilitated.

“The mandatory sentencing schemes before us violate this principle of proportionality, and so violate the Eighth Amendment’s ban on cruel and unusual punishment,” Kagan said.

In a dissenting opinion, Justice Samuel Alito said, “When the majority of this court countermands that democratic decision (by state legislatures), what the majority is saying is that members of society must be exposed to the risk that these convicted murders, if released from custody, will murder again.”

Because of the ruling, court hearings are now held before sentencing to determine whether a possible life sentence is appropriate.

Earlier this year, lawmakers in Michigan introduced bipartisan legislation to ban minors from being sentenced to life without the possibility of parole. At least 26 other states have passed laws prohibiting these sentences.

“The Supreme Court has made clear that life without parole sentences for young people should be rare,” state Sen. Sylvia Santana said. “The Michigan Supreme Court has placed the burden on the prosecuting attorney to prove by clear and convincing evidence that a young person is one of the rare people who should receive a life without parole sentence.”

Under the proposed legislation, juvenile offenders would be given a minimum sentence of no less than 10 years and a maximum sentence of no more than 60 years, with a possible parole review after 10 years, according to a news release from Michigan Senate Democrats.

CNN’s Ray Sanchez, Nicki Brown, Aditi Sanga, Lauren del Valle, Holly Yan and Bill Mears contributed to this report