In 1967, a Baltimore man named Howard Donahue began investigating the assassination of President John F. Kennedy. Like countless Americans, Donahue was fascinated by the events in Dallas. But what separated him from other amateur sleuths, and even the Warren Commission experts, was a lifetime's experience with guns and ballistics. In Mortal Error, Bonar Menninger chronicles Donahue's twenty-five-year investigation of President Kennedy's death and the stunning revelation it led him to. In crisp, rapid-fire prose, Menninger relates one of the greatest true-life detective stories ever told. More important, he offers solutions to questions that have haunted America for 50 years.