I find it unimaginable that he couldn't get a congressional aide out on bail without spending the night.
Of course, the whole idea of an aide to a senator getting thrown in jail for the night for what seems obvious to have been a simple misunderstanding reflects poorly on the capital police as well as Webb and his senate staff.
I mean, you carry a knife through airport security, they just take the knife and yell at your. They don't throw you in jail on your birthday.
So my opinion, maybe uninformed, is that the reason he was stuck overnight was that Webb said he didn't give him the gun, thus suggesting that the guy was not operating under his authority or with the right to have the gun.
We should of course also be lambasting DC for throwing the guy in jail. It should have been clear to them that the guy was not a criminal, was not trying to commit a criminal act, and was not a risk for flight or a danger to others.
I am surprised SWAT didn't raid his house looking for the rest of his arsenal.