Hostile Intruder

Remain calm, do not confront.
If possible to safely escape area, do so quietly and quickly (keep hands empty and visible to enforcement personnel).
If safe escape is not possible, lock or barricade yourself in the safest place you can quickly get to.
Call 9-1-1 and give your location.
Turn lights off, remain quiet, out of sight and take cover near concrete walls, file cabinets or whatever is available and keep away from windows and doors.
Turn off cell phone ringers.
Do not open door, or respond to voice command until you can confirm it is a police officer or University official.