Mortal Error: The Shot That Killed JFK (1992) by Bonar Menninger (ISBN 0-312-08074-3) alleges that while Oswald did attempt to assassinate JFK and did succeed in wounding him, the fatal shot was accidentally fired by Secret Service agent George Hickey, who was riding in the Secret Service follow-up car directly behind the presidential limousine.  The theory alleges that after the first two shots were fired the motorcade sped up while Hickey was attempting to respond to Oswald's shots and he lost his balance and accidentally pulled the trigger of his AR-15 and the shot fatally hit JFK. Hickey's testimony says otherwise: "At the end of the last report (shot) I reached to the bottom of the car and picked up the AR 15 rifle, cocked and loaded it, and turned to the rear." (italics added).[501] George Hickey sued Menninger in April 1995 for what he had written in Mortal Error. The case was dismissed as its statute of limitations had run out.  The theory received public attention in 2013 when it was supported by Colin McLaren's book and documentary titled JFK: The Smoking Gun (ISBN 978-0-7336-3044-6).  LBJ apparently believed this and there was a report of gunpowder smell at ground level that day. Oswald was high above on the sixth floor. Carcano used by Oswald also drilled neat holes - unlike AR-15 rounds.