On Tuesday, Chippewa Falls Police Chief Matthew Kelm announced they had a suspect in custody — a juvenile.
"The suspect was not a stranger," the Chief told a press conference. "The suspect was known to the victim."
"We do not believe there is any danger to the community."
"While nothing will bring Lily Peters back or change what happened, we are very grateful to be able to deliver this news for the family and for the community," the Chief added. "Driving through town and through our communities, we can see the purple ribbons – and honestly, I expect nothing less from the Chippewa Falls community."
He said a tremendous amount of work had gone into the investigation at the federal, state, country and local level, and law enforcement had been working 24/7 on the case; he thanked the public for over 200 tips they received, which were "critical" to solving the case.
He did not reveal the exact age of the suspect, nor how they knew the victim, but did refer to the suspect as "he".
The cause of death also remains unknown.
Neighbor Jeremy Machnik, whose children often played with Lily, told KSTP he frequently saw the child riding through the area on her bike.
"I grew up here all my life, never heard of anything like this," he said. "It's a scary situation when you know … we're just inside the house … and it's Sunday afternoon, we're cleaning and making dinner and that's going on a block away from our house and it's scary."