You might also ask, if you did wish to bring a firearm in with you, HOW would you go about that? Obviously there's security in the building and you would never be able to get that firearm more than a few feet from the entrance of the building.
Now if you had the personal authority or "pull" you surely could…
You could sidestep security altogether I suppose. Or you could come in after hours and drop a firearm somewhere in your chambers. You could ask a Bailiff to bring it in for you. Maybe there's a bunch of other ways if you have the robe and the ability to do whatever you please regardless of the legality of it.
