At the heart of the mystery of who killed John F. Kennedy lies the puzzle of Lee Harvey Oswald. Marking the thirtieth anniversary of the Kennedy assassination, FRONTLINE presents an investigative biography of the man at the center of the political crime of the century. The program follows Oswald's life story from his boyhood to Dallas, 1963. Was Oswald the emotionally disturbed lone gunman of the 1964 Warren Commission Report? Was he, as the House Select Committee on Assassinations concluded, only one of two gunmen that day in Dallas? Or was he an unwitting 'patsy' for the real assassins, as Oswald himself claimed when he was arrested on November 22, 1963?