DETROIT (AP) — Prosecutors said they’ll seek a life sentence with no chance for parole for a 16-year-old boy who killed four fellow students at a Michigan school and pleaded guilty to murder and terrorism.

They disclosed their plans in a court filing Monday, three weeks after Ethan Crumbley, 16, withdrew a possible insanity defense and acknowledged the shooting at Oxford High School in November 2021.

A first-degree murder conviction typically brings an automatic life prison sentence in Michigan. But teenagers are entitled to a hearing where their lawyer can raise mental health and other issues and argue for a shorter term.

Crumbley pleaded guilty to all 24 charges. The sentencing process is scheduled to start in February.

“A sentence of imprisonment for life without the possibility of parole is appropriate in this case,” Oakland County assistant prosecutor Marc Keast said.

Crumbley was 15 at the time of the shootings at Oxford High, roughly 30 miles (50 kilometers) north of Detroit. Four students were killed, and six more students and a teacher were injured.

His parents, James and Jennifer Crumbley, are jailed on charges of involuntary manslaughter. They’re accused of making the gun accessible to their son and ignoring his need for mental health treatment.