I have not done any empirical research into this, but I have noticed that there are certain police departments you don't see having tons of issues in the news,

I have not done any empirical research into this, but I have noticed that there are certain police departments you don't see having tons of issues in the news, so my theory is that in some departments the culture of having high integrity and doing the right thing might be the norm. You sometimes see this come out where one department refuses to cover for another department or its officers doing bad things. Obviously the goal would for that to be the norm instead of the exception.