Police are investigating a handwritten note with a bomb threat that a Pine Lake Middle School student found in one of the boys restrooms on Monday afternoon.

“We don’t believe the threat was credible,” King County Sheriffs’s Office spokesperson Sgt. Cindi West said in an email Tuesday morning.

The student notified a staff member about the note, which identified “D.B. Cooper” as its author, according to an email alert that school principal Michelle Caponigro sent to school families.

Police conducted a preliminary building search but did not find any indication of credibility to the threat, Caponigro noted. The King County Sheriff’s office and a canine unit also swept campus after school for precautionary measures.

School administrators anticipate Pine Lake will operate on its normal schedule on Tuesday. However, if police discover anything during the search, the school will notify families via Enews.