I don't know much at all about the Mongol conquests, but the holocaust was perpetrated by....a government, included the police of the government. The genocide in Rwanda was perpetrated by....a government, including the police of the government. You seem to clearly admit that the police in Mexico work for the drug cartels. So really I don't understand your post. I mean, clearly redfunguy is wrong to think that there have not been people roughly equivalent to police for much of human history, but all of the examples you gave were examples of out of control government and police agencies (Heard of Gestapo? Heard of Stasi?) murdering their own citizens. So really I think you just gave some good examples that show "just doing a job" is not a fucking excuse for the behavior of the police, or are you a Nazi apologist ?