Stationed at Los Alamos from 1944 to 1946, machinist David Greenglass had access to classified atomic bomb components. In 1945, he provided the Soviet Union with detailed sketches of high-explosive lens molds, which the FBI considered crucial to their bomb program. Arrested in 1950, Greenglass confessed and became the star witness against his brother-in-law, Julius Rosenberg, and his own sister, Ethel. His testimony, which he later admitted contained exaggerations to protect his wife, Ruth, was