Who was Lee Harvey Oswald?

Edward Jay Epstein:

The Warren Commission concluded– rightly I now believe– that Oswald fired all the shots that killed the President. But conspiracies do not necessarily require multiple rifleman to accomplish their purpose. And what the Warren Commission could not absolutely rule out, as two of its members pointed out to me, was the possibility that Oswald had acted at the behest of others. After all, he had advertised his willingness to undertake a high-profile assassination by circulating photographs connecting himself to the shooting of General Walker. Any party who was monitoring his activities in Dallas, New Orleans or Mexico City could have discerned from them that he was a potential assassin awaiting a mission. With his mind set on such violent actions as hijacking a plane, blowing up the FBI office, or killing "any American," not much would be required to prod him to violence. He had sought liaisons in dangerous quarters and someone could have provided him with an inducement.