Read this story and then ponder how many good apples in the police department and prosecutor's office *absolutely knew* who was the real murderer was and conspired to railroad this lady to protect him.
I suspect part of the problem is that those looking the other way, or covering up for another member of the "fraternal order of definitely honest police officers", don't see themselves as a "bad apple."
Of course. Always covering those "protectors of the public". They never do anything wrong. They are the good guys and the public is the filthy, dirty, lying scum that needs to be put down.