Not true, some states domestic violence, restraining orders prohibit gun ownership.
The original Fire Arms Control act of '68 included misdemeanor's as well, though IIRC they rescinded the domestic violence because so many cops had domestic violence issues.
by its terms explicitly prohibits the use, attempted use, or threatened use of physical force against such intimate partner or child that would reasonably be expected to cause bodily injury; or (9) has been convicted in any court of a misdemeanor crime of domestic violence.
IIRC that show mainly films auctions in Cali. I heard on one episode that they can not legally keep guns nor automobiles bought in storage auctions IIRC. The auctioneer to sell the weapons even at a storage unit auction would need a Federal License right.