A Wisconsin teenager has been sentenced to life in prison for the 2022 killing of his 10-year-old cousin, Lily Peters. Carson Peters-Berger, now 18, pleaded guilty to first-degree intentional homicide in the case.
Chippewa County Judge Steven Gibbs accepted the plea and imposed the sentence on August 26. Peters-Berger will be eligible to seek release to extended supervision after 25 years. As part of the plea agreement, two additional charges—first-degree sexual assault and first-degree sexual assault of a child under 13 resulting in great bodily harm—were dismissed.
The plea concluded a case that had been heading toward a trial. A hearing scheduled earlier in August raised the possibility of a resolution without a jury.
Lily Peters was reported missing on the evening of April 24, 2022, after she did not return home from her aunt’s house. Her bicycle was discovered near a wooded area in Chippewa Falls, and her body was found the following morning. Investigators determined Lily had injuries consistent with blunt-force trauma to the head. A forensic autopsy later documented evidence of manual strangulation and sexual assault.
According to the criminal complaint, Peters-Berger told investigators that he and Lily were walking along a trail before he asked her to explore in the woods. He stated that he punched her in the stomach, struck her head with a large stick, and strangled her until he believed she was dead. The Wisconsin Court of Appeals later noted that Peters-Berger told police he had intended to kill and sexually assault Lily before they left the house.
Investigators said Peters-Berger then attempted to sexually assault Lily before leaving the area. He reportedly returned after learning she had been reported missing, moved her body, and covered it with leaves.
Peters-Berger was initially charged with first-degree intentional homicide, first-degree sexual assault, and first-degree sexual assault of a child under 13 resulting in great bodily harm. Due to the homicide charge, the case was handled in adult court from the outset.
Attorneys for Peters-Berger had sought to move the case to juvenile court, arguing that he would not receive adequate mental health treatment in the adult system. In January 2024, Judge Gibbs denied this request after a three-day hearing, ruling that while Peters-Berger had valid concerns about treatment, moving the case to juvenile court would not reflect the seriousness of the alleged crimes. The Wisconsin Court of Appeals upheld Gibbs’ ruling in September 2024.