I was wondering what does it take to be too mentally unstable to own a firearm. Who decides what is too ill for a person to safely own a gun? I know that if a person is found innocent by reason of insanity they loose the right to own a firearm but...what else decides? Does a person have to check into a clinic for schizophrenia to loose the right, or what? Does any of this show up on an FBI background check?