Many years ago, a woman sat in her car outside the apartment building where he ex-husband's parents lived. Her only previous claim to fame was as president of an Engelbert Humperdinck fan club. When the elderly couple emerges from the building, she ran them down, killing both. It didn't occur to anybody to hold General Motors (nor Engelbert Humperdinck) responsible.
At around the same time, though, gun control advocates were suing gun makers because their products had been used to kill people. It seemed illogical, but in the United States anybody is allowed to sue anybody about anything — and given the right juries, some of the suits might have been successful. In 2005, Congress gave gun sellers immunity from most such lawsuits.
This does not provide total immunity. If your gun, due to some manufacturing error, blows up in your hand when you are trying to kill somebody, you can sue the manufacturer. If an individual goes to a gun dealer and says, "I want to buy a gun to kill my inlaws," the dealer is responsible. Just lawfully providing a gun to somebody who later uses it to commit a crime is not punishable — and it seems to me that that is the way it should be.
Guns are designed to kill. When a product does what it is designed to do, it's hard to fault the manufacturer or the seller. If we want to eliminate gun deaths, the logical thing to do is eliminate guns — but it's much too late to do that, if ever there was a time when it was possible. It's probably too late, even, to reinstitute the expired ban on assault weapons. Too many already are out there.
So what can be done? I don't think background checks will do much good — but if all guns must be registered (including rifles and shotguns), and the last registered owner of the gun is held responsible for any crimes committed with that gun, people may be more careful with their weapons. It also could help to limit the quantity of guns any individual can register, to reduce the problem of "straw buyers."
Of course, that won't ever happen.