A judge sentenced a Michigan teenager to life in prison Friday for killing four students and terrorizing others at Oxford High School, after listening to hours of gripping anguish from parents and wounded survivors.

Judge Kwame Rowe rejected pleas from defense lawyers for a shorter sentence and ensured that Ethan Crumbley, 17, will not get an opportunity for parole.

Moments before learning his fate, the teen apologized and appeared to agree with his victims that the stiffest punishment was appropriate.

“Any sentence that they ask for, I ask that you do impose it on me,” the shooter said. “I want them to be happy, and I want them to feel secure and safe. I do not want them to worry another day. I really am sorry for what I’ve done. ... But I can try my best in the future to help other people, and that is what I will do.”

Life sentences for teenagers are rare in Michigan since the U.S. Supreme Court and the state’s highest court said the acts of minors must be viewed differently than the crimes of adults. But Oakland County prosecutor Karen McDonald said a no-parole order fit the Oxford case.

“It’s not a moment to celebrate,” McDonald said outside court. “It’s tragic. And the voices today, I think, profoundly show that.”

Indeed, Rowe’s decision followed deeply emotional remarks by families of the deceased and survivors who said the tragedy had irreparably turned their lives upside down.

Crumbley, who was 15 when he committed the shooting, pleaded guilty to first-degree murder and terrorism. He brought a gun to school, but his backpack was never checked, even after his parents were summoned that same day about their son’s drawings, which included a gun and words: “The thoughts won’t stop. Help me.”

“I am a really bad person. I’ve done terrible things,” Crumbley said in court Friday.

The judge said the shooting was planned well in advance, and he noted that the shooter had plenty of time to stop as he walked through school.