party members. In 1936, Oppenheimer became involved with Jean Tatlock, the daughter of a Berkeley literature professor and a student at Stanford University School of Medicine. The two had similar political views; she wrote for the Western Worker, a Communist Party newspaper. In 1939, after a tempestuous relationship, Tatlock broke up with Oppenheimer. In August of that year, he met Katherine ("Kitty") Puening, a radical Berkeley student and former Communist Party member. Kitty had been married before. Her first marriage lasted only a few months. Her second, common-law marriage husband was Joe Dallet, an active member of the Communist Party, who was killed in the Spanish Civil War. Kitty returned to the United States, where she obtained a Bachelor of Arts degree in botany from the University of Pennsylvania. There she married Richard Harrison, a physician and medical researcher, in 1938. In June 1939 Kitty and Harrison moved to Pasadena, California, where he became chief of radiology at a local hospital and she enrolled as a graduate student at the University of California, Los Angeles. Oppenheimer and Kitty created a minor scandal by sleeping together after one of Tolman's parties. In the summer of 1940, she stayed with Oppenheimer at his ranch in New Mexico. She finally asked Harrison for a divorce when she found out she was pregnant. When he refused, she obtained an instant divorce in Reno, Nevada, and took Oppenheimer as her fourth husband on November 1, 1940. Their first child, Peter, was born in May 1941, and their second, Katherine ("Toni"), was born in Los Alamos, New Mexico, on December 7, 1944. During his marriage, Oppenheimer rekindled his affair with Tatlock. Later their continued contact became an issue in his security clearance hearings, because of Tatlock's communist associations. Many of Oppenheimer's closest associates were active in the Communist Party in the 1930s or 1940s, including his brother Frank, Frank's wife Jackie, Kitty, Tatlock, his landlady Mary Ellen Washburn, and several of his graduate students at Berkeley. When he joined the Manhattan Project in 1942, Oppenheimer wrote on his personal security questionnaire that he had been "a member of just about every Communist Front organization on the West Coast". Years later he claimed that he did not remember saying this, that it was not true, and that if he had said anything along those lines, it was "a half-jocular overstatement". He was a subscriber to the People's