This chapter enters the Soviet Zone of Occupation in eastern Germany, where the first East German political police, K5, was formed to assist the Soviet occupiers in carrying out denazification investigations and conduct background checks on members of the new state administration. It provides a brief history of the Soviet security forces active in the Zone at the time, including the NKVD, headed by General Ivan Serov, and the NKGB, headed by Viktor Abakumov. It explores the context of occupation, denazification, and terror in which East German police officials were trained under these Soviet security authorities and the porous boundaries between Soviet and German legal authority in the Zone.