I’m kind of surprised that news stories haven’t been using the term “unregistered” to refer to legally-owned firearms in the states where registration of those guns isn’t required. It’s coming, no doubt.
Recently, there was some guy from Virginia that got hired to do some security work in DC for the inauguration. He got stopped at some checkpoint and was arrested or at least detained for some time because he had a pistol and 500 rounds of ammo in his truck. All perfectly legal in Virginia, of course, but not in DC. I suppose they could have charged him with having an unregistered firearm, but I don’t think they did because he was hired to do legit security work. Some people were freaking out and assumed he was up to no good because he had 500 rounds of ammo with him.