Asymmetrical warfare in California

The "manifesto" of the ex-cop accused of a shooting spree over the past week is probably just what you'd expect of someone gone berserk. He makes epic threats, promising to wage "asymmetrical" warfare with all the skills he learned from the police and military, but also offers himself as a cautionary case proving the need for stricter gun control laws. He quotes Thomas Jefferson on the need to water the tree of liberty with the blood of tyrants, then explains that he isn't referring to the federal government but to the LAPD only. He claims never to have been a bully yet boasts of his brutal attacks on anyone who every used the "N-word" on him, dating back to childhood. He wishes the first President Bush a full recovery from his recent ailments and regrets that he (the shooter, not Bush) will probably never get to see the next Hangover movie. He gloats over Mitt Romney's defeat but adds that he didn't vote for Obama because his favorite candidate had been Jon Huntsman. The manifesto is a loose baggy monster, an epic unburdening of one man's life and opinions. It's easy to assume that he at once has legitimate grievances with the police and is legitimately nuts. He was taught by the people who are supposed to enjoy the monopoly on the use of force in this country, and then was let go while his resentments festered and his arsenal apparently grew. It would seem that he crossed the line from "good guy with a gun" to "bad guy with a gun" sometime before he embarked on his current rampage, while his arsenal remained intact. The man himself seems to recognize that something's wrong with this picture. What might the sane conclude?