Our governments have thousands of Dorners, and Loughners catalogued for future use. They’re drugged with Prozac or equivalent poisons that turn them into psychotic mass killers.
What do we do about it? - Seriously.
.
Nothing...
They've poisoned the minds of the past two generations of kids in government public schools, who were taught by unionized government employees of the state that the founders were racist and portrayed white people as evil racist. Dorner saw racist around every corner. He was a paranoid lunatic and a product of the government's culture of corruption and political correctness.
It's the reason LAPD hires the mentally ill and totally unqualified, and the reason why our electoral process has been undermined, compromised and the reason why the brainwashed masses are electing people like Obama.