 Complete the following phrase:  Following the establishment of the Soviet Union in 1922, in his capacity as a senior figure in the Communist Party, he was elected as a Full and Candidate Member of the Central Committee of the Communist Party of the Soviet Union from 1924 to 1934, Secretary of the Kazakh Regional Committee of the Communist Party from 1925 to 1933, and Chief State Arbiter of the Council of Peoples Commissars of the USSR from 1933 to 1939. He is best known for his involvement as one of the primary perpetrators of the killing of the Romanov family, as well as for the deadly role which he played in the Sovietization of Kazakhstan, , , a reference to the 