The thinking about this issue is 180 degrees out of phase. Instead of trying to keep guns from outlaws, we should be keeping outlaws from guns (keep them locked up if they're so dangerous).
Indeed, gun control is a fantasy. It will never keep anyone from being armed, good men and criminals alike will always find a way to be armed. If one is too dangerous to possess arms? Then that person should either be locked up or executed, those are the only methods of crime-prevention that have a 100 percent success rate!