Background checks are nice but they will only show convictions and they do not always predict future behavior.
If someone has a history of convictions for violent things, okay fine, they don't get a gun (legally). But it doesn't solve the problem of people getting guns who were 1) never caught doing bad things, 2) go crazy later, and 3) get guns illegally. Therefore it doesn't make sense to prevent the law-abiding population from arming themselves.
If someone has a history of convictions for violent things, okay fine, they don't get a gun (legally). But it doesn't solve the problem of people getting guns who were 1) never caught doing bad things, 2) go crazy later, and 3) get guns illegally. Therefore it doesn't make sense to prevent the law-abiding population from arming themselves.