> That is not a legitimate policy goal. The earlier poster points out that gun ownership is not correlated with crime at all. We shouldn't set policy goals that are merely about partisanship -- trying to cut down on gun owners because we don't like them -- rather than a clear public benefit.
A 2014 review in the Annals of Internal Medicine concluded having a firearm in the home, even when it’s properly stored, doubles your risk of becoming a victim of homicide and triples the risk of suicide. [0]
Guns are intrinsically dangerous, in much the same way as certain aggressive dog breeds and industrial explosives. While many/most people can safely raise rottweilers, store dynamite, and keep guns, some will not. Is there a marginal benefit associated with the removal of each marginal gun? Obviously. Is gun ownership reduction a legitimate policy goal? Obviously. It's strange that you think otherwise.
> In general, modern legal systems reject holding one person responsible for the crime of another. If a mass shooter lawfully purchases a firearm, what possible liability could a dealer have?
Part of a more involved system of background checks would necessarily involve more action by dealers to verify that the customer's purchase is legal. Prosecuting and holding liable individuals who fail to follow established precautions when selling dangerous products is not unusual.
[0] https://annals.org/aim/fullarticle/1814426/accessibility-fir...