[Editor's Note: The following is a speech delivered by DRGO's Dr. Robert Young to the 2015 Gun Rights Policy Conference in Phoenix, Arizona September 27.] It has appeared that almost all mass murderers have some kind of mental illness. Only about half of them are known to have had treatment. Mass murder victims are actually just a fraction of a percent of victims overall, so objectively it is not the main problem of people killing people. But since there is a lot of attention to mental...