Hi Lilac...I don't know where you are in the game for sure as there are many visits to this spot. If you have the security system set up correctly, you won't get caught. Did you already access the secret computer room, get the systems (various boxes) all set up:
Movement Sensor
Body Heat Sensor
Pressure Pads
Alarmed Doors
Video Surveillance
Sounds like you've triggered something.
Love, Witchen =O)