Since immediately after President John F. Kennedy's assassination on November 22, 1963, a number of conspiracy theories have been expounded by various different writers. One of the more difficult theories to believe is that a Secret Service agent accidentally discharged his firearm and killed President Kennedy.

In a 1992 book titled “Mortal Error: The Shot that Killed JFK” author Bonar Menninger espoused this very theory that had been developed by gunsmith and marksman Howard Donahue.


  In 1967, CBS created a television investigation of the Warren Report. Donahue was one of several experts who test fired the same model of the Mannlicher-Carcano rifle that Lee Harvey Oswald had allegedly used to assassinate President Kennedy. Donahue was the only one of these experts who had been able to fire the three shots within the same 6.5 second time frame as Oswald.  

This 1967 experiment led Donahue to begin his own investigation into the assassination, poring over the ballistic and forensic evidence. In the end, he concluded that Secret Service Agent George Hickey had accidentally fired what proved to be the fatal shot.

In order to believe this theory, the reader has to accept that Lee Harvey Oswald acted alone, that he was in a corner window of the sixth floor of the Texas School Book Depository with the Italian made 6.5 Mannlicher-Carcano rifle, and that Oswald did fire three shots at President Kennedy.  

Hickey was in the car behind the President’s open limousine during the motorcade through Dallas.

 Some writers have claimed that when Oswald began shooting, Hickey's car made an abrupt start just as Hickey had grabbed a Colt AR-15 rifle. This erratic movement caused Hickey to lose his balance and accidentally discharge his weapon. There is uncontroverted evidence that Hickey had such a high powered weapon in his hands on that fateful day. Photographs taken during the very moments when Kennedy was first shot show Hickey holding what appears to be a high powered rifle in the car immediately behind the president's open air limousine. The Warren Report contains two sentences about Hickey, stating that after hearing what turned out to be the third shot fired, he picked up and cocked an automatic rifle. He kept this at the ready the entire way to Parkland Memorial Hospital.

Central to this accidental assassination theory, are the locations of the entrance and exit wounds from the President’s skull, the diameters of those wounds, and the trajectory of the bullet that caused the fatal blow.  In addition, Donahue took into consideration the few witnesses who had testified that they had smelled gun smoke near the President’s motorcade as Kennedy was being shot. 

Based upon Menninger’s book, an Australian homicide detective named Colin McLaren began his own investigation.  He examined the volumes of evidence that had been released by the Warren Commission and concluded that combining the evidence with the law of physics meant that Kennedy's assassination was the result of this very tragic accident.  In 2013, the movie "JFK: The Smoking Gun" based on Menninger’s book and McLaren’s findings premiered on cable television.

This theory has been widely criticized and lacks credence with most assassination theorists.  One should be note that there has never been a single eyewitness who has claimed that he or she observed Hickey fire a shot on November 22, 1963.  There were seven other individuals who were in the same car as Hickey and none of them have even claimed to hear a shot coming from their car.

More important is the fact that Hickey adamantly denied that he fired his weapon that fatal day.  In 1995, Hickey filed a libel suit against Menninger, Donahue and Menninger’s publisher – the St. Martin's Press.  The lawsuit was dismissed due to a statute of limitations defense. Nonetheless, at least one of the defendants settled with Hickey in order to avoid further legal action.