I'm not sure from where are you getting all this? Who says that the "New York City Police Department is a separate law enforcement agency type like the FBI'"? 
 The Police in New York city is called the New York City Police Department. The Police in New York state is called New York State Police. Exactly like the mass killings committed by communist regimes are called by Helen Fein  "Soviet and Communist Genocides and 'Democide" in Contextual and Comparative Studies I: Ideological Genocides; Valentino calls the killings under communist regimes "communist mass killings" in Final solutions: mass killing and genocide in the twentieth century etc. Rummel calls the killings in the Communist countries "Communist democide". What has the FBI to do with anything here?