Sign up for the daily CJR newsletter . On June 13, 1976, a source invited Don Bolles, an investigative reporter who covered crime, corrupt politicians, and the Mafia, to a meeting in a Phoenix hotel. The source didn’t show up. When Bolles got back into his car and turned the key, his vehicle exploded. He died in the hospital eleven days later.  Jeremy Duda, a reporter for Axios Phoenix , has long been interested in the case. “But I was surprised to find that there’d never been anything resembling a comprehensive history of it written,” Duda told me. “Probably the most comprehensive history was one published in the late 1970s, not too long after the bombing.” Conspiracy theories about the case abound. Some think that John Adamson, a thirty-six-year-old racing dog owner who was convicted of the murder, was covering for the real killers; some even think the police and the Arizona attorney general’s office were in on it. In his new book, Murder in the Fourth Estate , Duda dispels those notions.…