To do what your proposing would require registration. His many sales would or could still happen without a license? Crooks would still be crooks and still get guns. No amount of laws will stop it.
We just need to be firm with the punishments . That would help when they get caught.
I understand where you are coming from. I wasn't thinking necessarily about a license to own or a registration just essentially a license that would only provide the same information I have to now when I buy a new gun. Just to make the process easier.