DECATUR, Ill. (WAND) - The Keil Administration Building, which acts as the headquarters of Decatur School District 61, was struck by a bullet.

Detective Sgt. Chris Copeland told WAND it was most likely a stray bullet that went through a third floor window of an employee's office. 

Copeland said it came to rest on the window sill after only penetrating a single pane of glass, which suggests it was fired from a significant distance.

The employee found the bullet Monday morning. She had last been in the office Friday.

Police are investigating to see if they can learn where the bullet was fired from.

DPS released a short statement saying, "All is well at the Keil Building. We appreciate the response and thorough investigation by Decatur Police."