Police said a 13-year-old made a threat to the Hogan Middle School in Vallejo on Instagram Thursday.
Parents and Vallejo City Unified School District officials notified police about the threat and police identified the boy and went to his east Vallejo home, Capt. Jason Potts said.
Police searched the home and the teen admitted his involvement in the threat.
No other suspects were identified or involved, Potts said. Anyone with information about the incident is asked to call (800) 488-9383.