Yah, here in WA too. I think courthouses are pretty universally off limits. Not that it stops stuff like this, of course...
In NM it isn’t illegal, though there are signs saying it will be prosecuted it cannot be done legally because the State’s Constitution prohibits it (Art II, Sec 6).
In fact, considering this case, and the multiple USSC cases where they said that the police have no affirmative obligation to any [particular] private citizen’s protection; any court which demands your presence w/o charges yet disarms you (ie jury duties) is abridging your right to protection.