On August 16, 1937, he became the head of the board of the labor camps GULAG NKVD five days after the beginning of Polish Operation of the NKVD. According to NKVD documents, 139,835 Poles who were citizens of the USSR were convicted in 1937. Of this number, 111,091 Poles were directly killed, and 28,744 Poles were sent to GULAG camps.