Instead, let's talk about how to identify shooters and keep the guns out of their hands.
Can't be done.
For example, in the most horrific instance of gun violence where twenty six-year-old children were killed, the shooter did not own the guns. The assault weapons belonged to his mother, who was presumably sane and had not ever assaulted another person. Had the guns been outlawed, she would not have had them.
Training sights on the mentally ill rather than the ability to obtain assault weapons will not lead to less gun violence. In fact, our ability to identify those with homicidal tendencies is just plain awful. The better the psychopath, as with Columbine killer Eric Harris, the better they are at masking their ideation.
The craziest looking people will not ever attempt to assault another human being, although their language may lead us to believe they are dangerous.
And all too often, the most dangerous people are untouchable, with special interest groups like the NRA protecting their right to bear arms.
If we were to attempt to keep guns away from those who appear the most dangerous, this guy would be number one on my list: