The two most sought after items to steal in home invasions and robberies and B & Es, are drugs and guns. Cash and valuables are only 3d.
Any person who has a criminal record (or any other kind of record) that will come up in a standard FFL background check (that already exists) that makes them lawfully ineligible to buy and own firearms never buy guns from FFLs. If they are caught doing so, it's another felony (IF anyone will prosecute it, and there is a long history of chronic failure to prosecute it).
They steal them or buy them from other criminals. And prices are generally cheaper than FFLs too.
While private sales (in states that don't require them all to go through an FFL; the so called gun show
loophole) do occur, criminals are not known to pursue many private sales (except from other criminals).
It's my experience that private sellers (without an FFL background check requirement) are extremely careful and vigilant about who they sell to if it's not to known friends or family. Many private sellers require a buyer to show a state issue CCW to make a sale, and you can't get a CCW without a full background check to ensure you are a lawful firearm owner. It does happen, but not that often.
No lawful owner ever wants to sell to a prohibited person. If they don't require a CCW, they require a driver's license and other ID, compare photos to the buyer, and write down the name address and other data and keep it for their records.
A national required background check for all private sales is not going to stop any criminals from getting guns.... the same way they always have. But it is a good way to add information in creating a national registry of private firearm owners.
While our current administration is handing out "Free stuff" ...maybe they should hand out free gun safes so guns will be less likely to be stolen in home invasion...just a thought.....But seriously , maybe giving a huge tax credit for purchasing one might be a thought.