I think definitely places with a certain number of people present should be required perhaps to hire armed guard(s), have metal detectors or allow CC or OC. The only gun control is no guns and that wont happen. Previous poster was right, its already illegal to shoot people. Or if you have had contact with some form of psychiatric Dr. or meds then you cant get a gun, legally.
That would be millions of people the vast majority of whom are no danger to anyone.