He was a killer, and probably crazy, at that. Nevertheless, there's a lot of hand-wringing over how he died. Once the cabin caught fire, he probably could have tried to flee, but it's likely he would have been shot trying to escape. Then the cops would have criticized for shooting him in the back. No matter how this turned out, it would have been ugly, and everyone would have been second-guessed. Once he killed the couple in LA and ambushed the cop, his "rights" went out the window.
Oh, and one other thing: he was fired from the LAPD in 2008, right? So it would appear he's been getting ready for this for four years.