Investigators now believe 13-year-old Madeline Soto is dead after discovering her backpack and school-issued laptop in a dumpster, Orange County Sheriff John Mina announced Friday.

Her mother’s boyfriend — Stephan Sterns, who is jailed in Osceola County after being arrested in Kissimmee for sexual battery and possessing child porn Wednesday — is the prime suspect. The Kissimmee Police Department has taken over efforts to recover Madeline and the investigation into her presumed murder.

Police Chief Betty Holland said Sterns was driving through Kissimmee in a silver 2010 Lincoln MKC with a flat tire around the time Madeline was last seen. She called on the community to contact authorities if they have any information on the car or Madeline’s disappearance.

This is a developing story. Check back for updates.