People are very quick to let each other off the hook.

You buy guns, you own guns, you have guns around the house..And not like the guns I grew up with, a rifle for deer season and a shotgun for bird season. You behave in ways that contribute to America's gun culture. You have guns designed specifically to kill people and have no other purpose.

Then your kid goes out and shoots someone with a gun design specifically to kill people. It doesn't take Einstein to follow that up chain of logic.