It appears to be an STG 44. I do not believe there is any provision in the law allowing the woman to sell it to anyone. A lot of people have paid fines or ended up in jail because of this stupid law. Maybe some people will understand it a little more if there ever is a followup to this story, which I forecast there will not be, unless it is a constitutionalist that does it on the interwebs.
There is not even a provision in the law allowing the woman to turn it in.
Gun buy backs usually extend an overall amnesty on the possession of the weapon.
Lots of murder weapons have been turned in and no has been prosecuted.