Cougar wrote:

There are literally hundreds of thousands of mentally ill, bi-polar, manic depressive and over all schizo psychopaths out there in the country today but not all of them will necessarily go shoot up a school or a postal office.  I'd guesstimate that under 0.11111% of the mentally ill do acts such as this.
Still, it would help, or at least diminish the potential damage, if the hundreds of thousands of mentally ill, bi-polar, manic depressive and over all schizo psychopaths wouldn't be able to walk into a gun store and pass all background checks when buying a gun.

This, at least, is something that can be prevented by government action.