We may never know for sure why Lovelle Mixon killed four Oakland cops, but the revelation that DNA evidence had linked him to a rape provides another possible motive. Or does it? There is no doubt that a rape conviction would result in far more prison time than a parole violation - the other possible motive for why Mixon went on his cop-killing rampage. But at this point, it seems unlikely that he would have suspected that cops were after him for the rape case. According to the Chron, the rape victim did not know her attacker. Moreover, Acting Police Chief Howard Jordan told the newspaper that Oakland police may have had a "run-in" with Mixon in the days before the shooting. So if cops didn't arrest him then for rape, why would Mixon think they would arrest him for it a few days later? It doesn't add up. Mixon would not have known that investigators had discovered the DNA link a day before the shootings.
From what has been reported so far, it's pretty clear that Mixon was one bad dude who probably got away with numerous crimes over the years - not just rape. In fact, police strongly suspected him of murder in a December 2007 case but couldn't prove it. Not surprising, since Oakland police have the worst record for solving violent crimes among large police agencies in California. In short, Mixon would have had little reason to believe that cops could get him on the rape case - or any other crimes he likely committed over the years. But as a parolee, Mixon had to know that the cops would certainly come after him at some point for violating his parole. He knew they could prove beyond a doubt that he failed to show up to a parole meeting in February - and that it meant an automatic return to prison.
Now having said all that, it does seem within the realm of possibility that Mixon might have thought that his luck had finally run out. He could have been worried that cops finally had the goods on him for the rape, or the murder case, or some other crime he got away with. And so when the motorcycle officers pulled him over on Saturday, the panic of being caught for any of those things and being sent back to prison (including the sure-thing parole violation) may have sent him over the cliff. It's possible, but the truth is, we'll likely never know. Let's just hope that the possible rape-case motive doesn't blur the fact that the state's parole system is broken.
Update: The Los Angeles Times has a great tick-tock on Mixon since his last release from prison on November 1. It's seems clear from the timeline that Mixon was hiding out from his parole officer for several weeks by the time OPD rolled up on him on Saturday (hat tip: Charlie Pine).