Who are the Forerunners of the KGB?

The N.K.V.D was Stalin"s counter-terrorist Right Arm, and the initials stood for National Commissariat for Internal Affairs, sort of a combination of Gestapo and F.B.I. there were both uniformed and plainclothes N.K.V.D men, among other ( credits) responsible for the so-called St. Petersburg Massacre ( actually occurring at Ekaterinberg or city of Catherine) and in Czarist times, Catherine II organized a homeland security squad under Major Potemkin.