some of these guns have been sold in-state person to person, or at gun shows in the parking lot. No documentation (and some have been, in fact, stolen at some point in the past). No use in asking for trouble, whether spurious or correct, the accusation can cause real problems, and if true, the pistol reverts to the wronged owner, all others simply eating their losses. Hide the last 2 or three digits of the serial number from the public.
