When a gang member speaks out against unethical activity to another gang member, they get weeded out quick. I’ve been told by former officers that they had to either defend their colleagues criminal activity, incriminate themselves, or lose their job. It’s inevitable that a gang of that size with 0 oversight will quickly become rotten to the core. In my town, they’re essentially a government sponsored criminal organization.
It's not just your town or a local phenomenon, quite the contrary. For the reasons you've succinctly outlined, it's like this everywhere in the USA.