However, the prosecutor often is beholden to local police departments to prosecute other unrelated crime. Most DAs don't have the ability to bite the hand that

However, the prosecutor often is beholden to local police departments to prosecute other unrelated crime. Most DAs don't have the ability to bite the hand that feeds them. If a DA comes out and says "hey, I'm investigating a racket that is put on by local cops" those local cops (and their union) will fight tooth and nail to remove that DA, no matter how effective their other investigations are. If that AG or DA is out of a job, and try to spill the beans, they can be threatened, or ignored outright by local media or other prosecutors who have legitimate reasons to not rock the boat. Organized corruption begets more organized corruption.