Timeline of events:
- An unidentified woman working in the Governor Office Building hears an announcement over an intercom system that a possible hostage situation was in progress on the fifth floor.
- The woman informs her superior.
- Her superior calls the alarm company, Sonitrol.
- 10:02 a.m. - Sonitrol contacts the Jefferson City Police Department, prompting an immediate reaction from the department.
- Responding officers secure the main floor and call for additional tactical units.
- 12:30 p.m. - Tactical teams begin searching the building, floor by floor. Workers are allowed to leave as each floor is cleared.
- 2 p.m. - The last floor of the building is cleared. Approximately 155 people have left the building.
- 4 p.m. - The Jefferson City Police Dept. holds a press conference and says an investigation is ongoing.
- Jefferson City Police Dept.
- Missouri State Highway Patrol
- Cole County Sheriff's Dept.
- Missouri Water Patrol
- Capitol Police
Source: Jefferson City Police