"Oswald defected to the Soviet Union for a while and came back to the States after he realized life over there wasn't the communist paradise he thought it would be."

Too true! They weren't Marin County types. They may have five guys on a site to do what two could do--but they expected you to work.

"...his "I'm a patsy" statement suggests that he was telling the press that he was being falsely accused of the assassination because of his political views."

In much the same way that every thief and murderer called himself a 'political prisoner' during the same time period.