Then where are all these good cops clearly speaking out that this was an illegal chokehold and it was murder? Instead of remaining silent or spinning it to support their dude?
Most people only look out for themselves. They want to keep their job, so they don't speak out. This makes them complicit, no doubt.
Even good cops should be criticized in certain cases where they don't speak out (if they know something was wrong, or if they in general see shit that is wrong in their line of work). Although as has been said before, the whole thing is fucked. Departments and unions make it pretty hard for cops to come forward. Believe it or not, cops all the time speak out (not to the media), but try to speak out against practices in the department, and get shut down or get run out.
That said, if you want to argue they should be speaking to the media (and be out of their job), that is a valid criticism. I still think this is an issue that society on a whole should be speaking out against too though. Where all the "good people" that aren't outraged? Why is it that only blacks and a handful of people are getting angry. Why is the majority of society sitting idly by, and okay with this? Well, probably because it doesn't effect them.
So that's why they have no room to complain about riots and violence when they wouldn't do a damn thing about it.