The man should have registered his guns. He did not and he is now paying a price. I liken this to driving an unregistered car, not a big deal it is an administrative error on his part.
He gets the guns back in the end and the he may have to register those guns where he moves to.
"While investigating the case, police seized Mr. Srigley’s pistol, which he said he purchased legally in Virginia when he lived there, and close to 100 rounds of ammunition from his home. Mr. Srigley told investigators that he owned two other guns — an antique M-1 rifle and a Mossburg 12-gauge shotgun — which were in a storage space in the District.
Police also seized those guns, but authorities have agreed they will return the firearms to Mr. Srigley when he registers them in Maryland, where he plans to soon move."
D.C. man won't face gun charges for shooting pit bull attacking boy - Washington Times