MADISON, Wis. (AP) — The cousin of a 10-year-old Wisconsin girl killed in 2022 pleaded guilty to first-degree intentional homicide on Wednesday and was sentenced to life in prison.

Lily Peters was riding her bike home from her aunt's house in Chippewa Falls on April 24, 2022, when Carson Peters-Berger persuaded her to leave a trail and explore the surrounding woods with him, according to the criminal complaint.

The girl's body was discovered the next day. An autopsy determined she had been beaten, strangled and sexually assaulted.

Peters-Berger, now 18, was 14 at the time of the killing. He was arrested the day after Peters' body was found.

Chippewa County Judge Steven Gibbs accepted his guilty plea on Wednesday and sentenced him to life in prison. Under a plea deal, two other charges — first-degree sexual assault causing great bodily harm and first-degree child sexual assault involving a child under 13 — were dismissed.

Peters-Berger's attorneys, Michael Cohen and Alicia Linzmeier, did not return emails seeking comment.

Peters-Berger's attorneys tried to get the case moved to juvenile court, where proceedings are secret. They argued that Peters-Berger would not receive the mental health treatment he needs in the adult criminal justice system.

But the judge refused, saying the offenses were too serious to warrant such a move. A state appeals court also kept the case in adult court.