Teen Killer Sentenced to Life for Murdering 10-Year-Old Cousin

On August 26, Carson Peters-Berger, now 18 years old, was sentenced to life in prison with the possibility of extended supervision after serving 25 years for the first-degree intentional homicide of his 10-year-old cousin, Lily Peters. The tragic incident occurred on April 24, 2022, when Lily went missing while walking near a trail in Chippewa Falls, Wisconsin. Her body was discovered the following day in a wooded area.

Peters-Berger, who was 14 at the time of the crime, confessed to police that he had followed his cousin down the trail and brutally attacked her with the intention of raping and killing her from the outset. According to court documents, Peters-Berger strangled Lily before sexually assaulting her. Afterward, he reportedly went home to take a shower and wash his clothes before returning to the scene to hide her body more thoroughly when he learned she had been reported missing.

In December 2024, Peters-Berger pleaded not guilty to adult charges of first-degree intentional homicide, first-degree sexual assault causing great bodily harm, and first-degree child sexual assault. His trial was scheduled for November but did not proceed as his attorneys attempted to move the case to juvenile court, arguing that he could receive better mental health treatment there. However, these appeals were unsuccessful.

Peters-Berger's guilty plea on August 26 allowed the case to conclude without a full trial. As part of this agreement, all other charges against him were dismissed. The judge sentenced him to life in prison with the possibility of parole after serving at least 25 years. Additionally, Peters-Berger was ordered to pay $30,197.20 in restitution and received four years' credit for time served.

The case has drawn significant attention due to its brutality and the young age of both the victim and perpetrator. Chippewa County District Attorney Wade Newell emphasized that Peters-Berger's actions were premeditated and exhibited a level of cruelty indicative of an adult, despite his juvenile status at the time of the crime.

The sentencing comes amid ongoing discussions about how to handle cases involving young offenders who commit violent crimes. Advocates for harsh penalties argue that such acts warrant severe punishment regardless of age, while others advocate for rehabilitation and addressing underlying mental health issues in juveniles involved in serious criminal offenses.