 He was an agent/group leader (gruppovik) and co-owner of a Soviet front company that manufactured gloves.The Venona project suggests he may have been implicated, along with Amadeo Sabatini, in the murder of Walter Krivitsky in 1941.After the death of Jacob Golos in November 1943, spotting and recruitment was taken over by Katz by mid–1944, while Elizabeth Bentley continued as manager and courier.