Some times, they're ALL bad guys.
....hmmmm. Something very familiar about that! With such a ratio, one has to realize that everyone in that environment would come into contact with the related criminal practices and attitudes regularly. They would, no doubt, be able to see "which way the wind blows" and to what degree the bad guys were able to get away with their dirty deeds.
The calculation of "does crime pay" would be extremely persuasive, as it is almost everywhere and with almost everyone. There might a obvious bandwagon on which to jump.
To wit, the upper echelons of the FBI.