He was not arrested on federal property, he was arrested by DC cops within their jurisdiction. Walter Reed is way the heck off the interstate, and isn’t exactly a sprawling institution.
It is good you have not been stopped while carrying contraband on federal property, but if you continue, you just might get that chance.
I have driven all over several military bases with loaded weapons, guns, ammo, etc. I had reason to be in some areas, but not all. Had I been stopped and searched (consent to search is automatic on military property) I would have been arrested, even though I meant no harm.
This guy screwed up and needs to do what his lawyer tells him to do. If he wanted to do business in DC, he needed to pick up his weapons after he was done with his appointments. Traveling “through” does not include local stops, case law abounds on this.
You really don’t understand the Quantico situation at all. Here are the rules as followed by the Quantico Shooting Club. http://www.quanticoshootingclub.com/rules-firearms-transport.php and there are some references in there you should look up.
They'll look it up for you at that time ~ if your friends couldn't find out.
That ploy works for all sorts of demonstrators. Also, not all public side walks are actually "Public' ~ nor are streets. There are "easements" on private property, and in some cases on "Federal installations", so if you get arrested there in that sort of spot you can actually win damages. The reverse is true as well as the Planned Parenthood folks found out ~ they had an easement on a public street, but only for passage ~ so the demonstrators could demonstrate right up against their front door. The demonstrators won in court.