Zachary Sklar, a journalist and a professor of journalism at the Columbia School of Journalism, met Garrison in 1987 and helped him rewrite a manuscript that he was working on about Kennedy's assassination. He changed it from a scholarly book in the third person to "a detective story – a whydunnit" in the first person. Sklar edited the book and it was published in 1988. While attending the Latin American Film Festival in Havana, Cuba, Stone met Sheridan Square Press publisher Ellen Ray on an elevator. She had published Jim Garrison's book "On the Trail of the Assassins". Ray had gone to New Orleans and worked with Garrison in 1967. She gave Stone a copy of Garrison's book and told him to read it. He did and quickly bought the film rights with $250,000 of his own money to prevent talk going around the studios about projects he might be developing.