[2] Evidence of Kramer's membership in the Communist Party USA (CPUSA) and his contacts with known Soviet agents comes from several sources: the direct testimony of Whittaker Chambers,[1] Elizabeth Bentley, Lee Pressman, and Nathaniel Weyl; the Venona decrypts; and the Moscow archives of the Soviet Foreign Intelligence Service (KGB).
Hope Hale Davis and her husband, Karl Hermann Brunck, were both members of the Communist Party of the United States (CPUSA).
Allen Weinstein has alleged out that Kramer was the head of a Soviet spy network (codename Mole later changed to Lot).
Kramer's report sent to Anatoly Gorsky on 19 October 1945, shows that Oppenheimer refused to pass on information from the Manhattan Project.
Kramer is supposed to have provided information to the Soviets from his position as staff member of the Senate Subcommittee on War Mobilization on a dispute among American policy makers concerning the French National Committee of Charles de Gaulle and an internal U.S. government investigation of German corporate links to American companies.
His contacts with Anatoli Gorsky, the legal Rezident, provided little information beyond what could be obtained from a newspaper article or overheard at a Washington D.C. restaurant.