Private security is, IMHO, a Gawd D*mn joke. And the security at the court house is no exception.
I routinely go into the court house and safety building wearing civvies. I use my department issued badge and ID at the checkpoint. They don't even look at it. They see tin and a card in a black wallet and wave me through.
I'll bet if someone flashed an old security guard badge and novelty ID they'd get let through with a weapon.