There are a lot cops that are "good guys" (not psychopaths) that will cover for the psychopaths in their midst. Hierarchical organizations like government or corporations will always be infested with and taken over by the most intelligent, ambitious and conscienceless. Yes it's a matter of taking out the bad guys but how do you identify them? Some people are only two of the three - intelligent and ambitious. Others may start out OK and turn into sociopaths over time. The age old problem of evil.