Sparknotes: Guy is fired from LAPD for "lying" about his supervisor's use of unnecessary force (when it appears as if he wasn't lying). He goes and murders the daughter and future son-in-law of the man who represented him in the disciplinary hearing. He then shoots at police officers in Corona and Riverside, hitting 3 and killing 1. His car is then found burned down in Big Bear, CA near Bear Mountain Resort.
Before most of this he posted a 11,000ish word manifesto of sorts to facebook stating that LAPD is corrupt and racist and that he will continue to target LAPD brass until they admit he was correct in his original report.
He is a former naval officer and sniper and is heavily armed.
At some point last night or very early this morning he appeared down in San Diego and tried to steal a boat, probably to escape to Mexico. He's been leaving evidence throughout Southern California.
The guy doesn't appear as if he wants to be caught, and finding him might be very difficult.
My guess is that he's somewhere in Mexico by now.
tl;dr: Guy killed a police officer and 2 other people, is on the run.