"Meat eaters" and "grass eaters".

The meat eaters were the officers that actively pursued opportunities to be corrupt and spent a great deal of time on the job engaging in corrupt activities instead of police work. The grass eaters were essentially normal officers who would turn a blind eye or do things that had been normalized such as accepting or soliciting small bribes opportunistically.

In the words of the report, "the grass eaters are the heart of the problem".

The reasons for that utter lack of prosecution leading to massive corruption is a microcosm of the broader circumstance to which you've pointed out.

Having read the Knapp Commission report, I am no longer of the view I have anything original to say on this.