https://en.wikipedia.org/wiki/Brady_Handgun_Violence_Prevention_Act The Brady Bill prevents felons and anyone with any domestic violence on their record (Or who's under a restraining order and considered a violent threat) from getting a gun, along with anyone with severe mental issues or who has been previously committed.Any sign of mental illness or domestic violence should be disqualifying (though I worry that this will prevent people from seeking help).
So? I can tell anyone, including my current medical provider, that I've never done so much as gone to a shrink before, but that doesn't make it true. And how are they going to check? All doctors take medical histories but they are completely dependent on the truth of the patients filling them out. If I said I'd never seen a shrink there isn't a receptionist on earth who would call the 50 counsellors in my immediate area to confirm that that's the truth. And since I wouldn't have told you who I had seen, that's what you would have to do.