The Lone Gunman Theory is the official explanation for the John F. Kennedy assassination, as arrived at by the Warren Commission after a review of the available evidence. According to this theory, the 1963 assassination involved a single gunman, Lee Harvey Oswald, who was deemed “emotionally disturbed.” This theory has been challenged by people who suspect that a conspiracy surrounds the Kennedy assassination.

According to the Warren Commission's conclusions, the Lone Gunman fired three bullets. One of his shots missed, while another hit President Kennedy's neck, passing through him and into the body of Governor John Connally. The third bullet penetrated his skull, causing a fatal head wound. This conclusion was arrived at on the basis of witness testimony and analysis of the forensic evidence, including bullets and fragments recovered from the scene.

Conspiracy theorists have challenged many aspects of the Lone Gunman theory. The magical “single bullet” which managed to hit both the President and the Governor has been questioned, under the argument that available information suggests that the trajectory needed to hit both men would have been physically impossible. Other theorists have said that multiple gunmen must have been involved in the assassination, arguing that Lee Harvey Oswald could not have fired all of the bullets from his stated position in the Texas Schoolbook Depository Building. Some people also believe that the wounds on the body of the President are inconsistent with the conclusions of the Warren Commission.

In the eyes of conspiracy theorists, the Lone Gunman theory has some major inconsistencies which make it implausible. Witness testimony in the case was quite varied and in some cases contradictory, lending further credence to suggestions that there may have been a conspiracy and cover up. All sorts of theories about who really killed John F. Kennedy have been bandied about, and some people treat the assassination as an unsolved case, despite the fact that the Warren Commission was evidently satisfied with its results.

As often happens in controversial and very public criminal cases, not all of the evidence from the JFK assassination matches. Witnesses can become confused, especially as the length of time after the event increases, and it is perhaps not surprising that there are conflicts in testimony. Forensic techniques in the 1960s also left something to be desired, making it hard to rely on the reliability of forensic evidence. The events of the Kennedy assassination riveted the attention of the nation, which may explain the long-lasting fascination with the case, even among people who were not even alive at the time of the event.