Probably the only reason that we would find out that they lied is because they did something like this VT incident. If they weren't killed during it the least of their legal problems would be providing false information.And if someone HAS been "adjudicated as mentally defective" and lies . . . can they be held legally accountable?
I'd like to find out some way to keep these folks from getting a hold of a gun in the first place. Like TXI stated - getting their medical records into a database might be hard to do because of confidentiality reasons, but if it's ever going to get accomplished it will probably be after a tragedy like this happens.