What? I never said you can identify specifically who will carry out a mass shooting. But, taking preventative measures against people more prone to carry out mass shooting doesnt require that. However I think if warning signs were paid more attention to and followed through with, and on top of that these killers didn't have access to guns because of their mental instability, we could dramatically decrease the frequency of firearms (automatic or otherwise) used for mass killings. It's just easier, more politically correct, and conistent with its anti-gun agenda, for the mainstream media to blame guns rather than negligent, unaccountable people who enable these events.
Off topic, but what's funny as in all of this is how the Hollywood elite is seemingly MIA in this entire debate. Not surprising given 90% of movies are based on to some degree gun violence and glorification.