The vice president of a Baton Rouge cleaning company has written a book claiming that his father is the Zodiac Killer, the man who killed at least five people in Northern California in the 1960s while sending letters and cryptograms to local newspapers. HarperCollins has been keeping Gary L. Stewart’s The Most Dangerous Animal of All under wraps for months, but New York Magazine reported its existence Monday. Stewart researched the book for 12 years, and HarperCollins says his story was vetted by its legal team. Tina Andreadis, a publicist at HarperCollins, was tight-lipped about the book’s content, though she did comment on Stewart. “He didn’t want to believe,” she said. “I don’t think most people want to know that their father is a notorious serial killer.”