Marion police responded to Vernon Middle School after they were notified of a student making threats inside the school to use a firearm at 10:41 a.m. Tuesday.
The threat caused a heavy police response and the school went into lockdown. Within ten minutes, the student was taken into custody and the lockdown protocol was lifted. The student was charged with first degree harassment.
Authorities say a fire alarm was pulled earlier in the day, but it isn't related to the threat incident.
The Marion police were assisted by the Iowa State Patrol, Linn County Sheriff's Office, and the Hiawatha Police Department.
Police say the investigation is on-going.