I still hold to the “bad apple” theory, in that the vast majority of LEOs are reasonable, within their rules.
Many years ago, somebody got a rude but accurate cop quote, that “the typical cop is like a (homosexual), in that if you (have sex) with him, he’ll (have sex) with you right back, but harder.” So, ahem, reverse ‘golden rule’ with cops. It is their unwritten rules.
Importantly, there are two very critical provisions to this.
The first is that the FBI and DEA both admit that there is considerable abuse of anabolic steroids by police, and combined with high stress levels, this can make a cop an unpredictable time bomb. This is exacerbated by police not wanting to crack down on one of their own.
The second problem is all the other problems combined, to include bribery, gambling, prostitution, narcotics, and good old fashioned mental illness.
But a single cop, or a peer-pressure group of cops reflects on the rest of their department, no matter how many good cops there are.
Unions!
You forgot to mention the unions.