Ron Morgans, who has worked as a picture editor at eight UK national newspapers, is now a fiction writer. In his latest book, Murder at the Royal Wedding, "a demented ex-con with a Princess Diana obsession plans to kill Camilla, Duchess of Cornwall" (at Prince William's wedding, presumably, since William's bride, the Duchess of Cambridge, is shown in the book's cover image). So far the book is available only on Amazon's Kindle e-reader.
2014 UPDATE: I don't recognize the current cover image so I think it has changed since I first posted this.