14-year-old boy in custody for slaying of 10-year-old Lily Peters

A 14-year-old boy is in custody for allegedly killing 10-year-old girl Lily Peters and leaving her body on a Wisconsin walking trail.

The defendant, an eighth grader who was known to Lily's family, made his first court appearance on Wednesday.

Prosecutors said in court that the defendant intended to "rape and kill the victim from the get-go." In his statement to police, the boy allegedly said he punched Lily in the stomach, hit her with a stick, knocked her to the ground and strangled her "to the point of death," before sexually assaulting her, officials said.

Lily, a fourth grader, was reported missing by her father on Sunday night, said police in Chippewa Falls, a city about 100 miles east of Minneapolis.

She had been at her aunt's house on Sunday and never made it home that night, police said.

On Sunday night, officers found Lily's bike in the woods by a walking trail near her aunt's house, police said.

Around 9:15 a.m. Monday, Lily's body was found in a wooded area near the walking trail, Chippewa Falls Police Chief Matthew Kelm said at a news conference.

On Tuesday evening, Kelm said police arrested an unidentified juvenile suspect.

"While nothing will bring back Lily Peters, we are grateful to deliver the news of an arrest to the family," he said at a news conference.

Judge Benjamin Lane on Wednesday set a $1,000,000 cash bond for the juvenile. The teen won't have contact with any other juveniles at the juvenile detention center. He'll return to court on May 5 to be assigned permanent counsel.

ABC News' Victoria Arancio, Matt Foster and Darren Reynolds contributed to this report.