JFK theories?

Lee Harvey Oswald was a riddle wrapped in an enigma shrouded in mystery if ever there was one. Evidence of varying reliability has linked Oswald to virtually every group that had a reason to want Kennedy dead. In the years before Kennedy's death, Oswald worked as a radar operator at U-2 spy plane bases, defected to the Soviet Union and married the niece of a KGB colonel. On returning to the US, Oswald propagandized for Castro's Cuba out of a New Orleans building he shared with an ex--FBI agent trying to overthrow Castro. In the fall of 1963, Oswald moved to Dallas where he had FBI contacts, got a job in a Texas Book Depository and was accused of killing the president.