 His partner was Sammy the Bull Gravano, the same guy that admitted to 19 murders. I found out that his father was a bigamist, that he had a second family with five kids in upstate New York. I found out that his father owned the house that Errol Flynn used to live in. None of these things I knew before I started writing the book. I really didn't know the guy I was writing about in a certain way. I knew about it in some ways, but I didn't know about it in other ways.