I agree with several other posters in their responses.
If this was at my workplace, then I would want the enforcement officers to go in force.. just in case. In this day when all these workplace shootings take place, I would hate to think the police would do otherwise.
If this story read " Man in office building is seen with gun, one beat cop goes to investigate and man shoots cop and 12 co-workers" Then everyone knocking the response in this instance would be like "Where were the cops.. they only send one cop in on a armed person in the middle of a work place?"
I would rather have them over react and find it was nothing, then under react and have a very bad outcome.