I sold guns for twenty years, before and after the brady bill, and the nics call in for background check.
when I sold a gun to a person after he was cleared by the background check, the dealers responsibility stops there, we have more gun laws than you even know of, bring back the death penalty.
gun laws are not the issue, the death penalty is, give the death penalty to mass murderers, and you will see a drop off in these killings.