Can't really believe this story.
1.I think the cop would took the gun and ran with it.
2. It is a full auto (machine gun) !
Without papers she would be a felon for having it!
If the person she inherited it from had papers, there is not problem.
If the cops took it and ran they would be Federal felons.
Without papers she would not be a felon, the feds merely would have confiscated it.