The below is condensed from a long Rolling Stone article:

...That time in Miami, with Saint [his son] by his bed and disease eating away at him and him thinking he's six months away from death, E. Howard finally put pen to paper and started writing. Saint had been working toward this moment for a long while, and now it was going to happen. He got his father an A&W diet root beer, then sat down in the old man's wheelchair and waited.

...E. Howard scribbled the initials "LBJ," standing for Kennedy's ambitious vice president, Lyndon Johnson. Under "LBJ," connected by a line, he wrote the name Cord Meyer. Meyer was a CIA agent whose wife had an affair with JFK; later she was murdered, a case that's never been solved. Next his father connected to Meyer's name the name Bill Harvey, another CIA agent; also connected to Meyer's name was the name David Morales, yet another CIA man and a well-known, particularly vicious black-op specialist. And then his father connected to Morales' name, with a line, the framed words "French Gunman Grassy Knoll."

So there it was, according to E. Howard Hunt. LBJ had Kennedy killed. It had long been speculated upon. But now E. Howard was saying that's the way it was. And that Lee Harvey Oswald wasn't the only shooter in Dallas. There was also, on the grassy knoll, a French gunman, presumably the Corsican Mafia assassin Lucien Sarti, who has figured prominently in other assassination theories....

http://blog.wired.com/27bstroke6/2007/04/who_killed_jfk_.html