From the liberal side of view-you'd need to require all private gun sales to be had with a NICS check/transfer. For local private sellers you'd need to meet at a gun store and do a proper transfer.
Keep in mind, it won't stop mass shootings. It will cause more (most?) people to do a proper NICS transfer. I'm not sure what that solves. But, it would limit the average felon (who cannot own a gun legally) from buying one from me because I posted one for sale on Armlist, Facebook, IG, or met him at a gun show. Because, for a private sale to be legal in Ohio... all he has to do is show me that he has an Ohio ID.
So, my mindset is that "something can be done". but, all it would do is get the rule-followers (like me) to follow the rules. The people that want to kill people with guns could: A. also be rule followers in obtaining guns... and B. easily skirt the rules and still get guns.
THE DIFFERENCE IS THIS: Liberals think it will solve something because most of them don't see what (we gun owners) see/know. I submit to you that it will not have the impact they hoped for.
It's just like watching pro football "that idiot running back should have shot that gap and gained 10 yards".... I can say that all I want. I've never actually played football, been around a locker room, understood what goes on behind the scenes, etc...