The Warren Commission argued that direct witnesses to the shooting, who immediately rushed en masse to the grassy knoll after the shots were fired, were fleeing the area of the shooting. In reality, the people present, including a dozen members of the security forces, in particular Sheriff Decker's team, who had given the order to investigate the area, all testified that they were running to the search for one or more shooters posted on the grassy Knoll. while Commission staff counsel
David W. Belin referred to this omission as "perhaps the biggest blunder" the Commission made. It did not interview John Fitzgerald Kennedy's personal doctor,
George Burkley, who was present during the shooting in the convoy of official vehicles then at
Parkland Hospital, on board Air Force One, then at Bethesda Naval Hospital during the autopsy. He signed the death certificate and also took delivery of the brain of John Fitzgerald Kennedy which is declared lost in the
National Archives. Concerning the conclusions of the Warren commission about the three shots, the practitioner had declared in 1967: "I would not like to be quoted on this subject". The ballistic reports conducted by the FBI and the autopsy reports were not the subject of any counter-investigation, which made the commission directly dependent on the work of the latter. The Warren Commission, by decision of Earl Warren, refused to hire its own independent investigators. However, it had its own investigative capacity thanks to direct access to the emergency presidential budget funds granted by President Lyndon Johnson when it was created, to conduct its own investigations. Thus the Warren commission was not informed by the FBI of the discovery the day after the attack, on November 23, 1963, by a medical student, William Harper, of a piece of
occiput located at the rear left in relation to at the position of the presidential limo during the fatal shot to the head. He had it examined by the professor and medical examiner, Doctor Cairns who measured it and photographed this piece before informing the FBI, on November 25, 1963. The latter received instructions not to make any publicity on this subject. It was the Attorney General,
Robert F. Kennedy, who, informed by a letter from Dr. Cairns transmitted to the Warren Commission, allowed the latter to question the practitioner. that as early as the beginning of 1964, the chief adviser,
J. Lee Rankin, had given the outcome of the results of the work of the commission: guilt of Oswald, the latter having acted alone. Even before the creation of the commission, on November 25, 1963, and a few hours after the assassination of Lee Harvey Oswald by Jack Ruby in the premises of the Dallas police, Nicolas Katzenbach, assistant attorney general, had indicated in a memorandum intended of Bill Moyers that: "The public must be convinced that Oswald was the killer; that he had no accomplices still at large; and that evidence was such that he would have been found guilty at trial" creating a political orientation of the results of the investigation, even before the start of the first official investigations and knowledge of the results. Its objective was to cut short the speculations of public opinion either on a plot of communist origin (thesis of the
Dallas police) or a plot fomented by the far right to blame the communists (hypothesis defended by the press of communist bloc formed around the
USSR). As early as the 1970s, official members of the Warren Commission questioned its work, in particular
Hale Boggs who criticized the influence of
J. Edgar Hoover, the director of the FBI from 1924 to 1972, who had centralized all of the information from the FBI agents before synthesizing it and transmitting it to the Warren Commission. He campaigned for a reopening of the file considering that the director of the FBI had lied to the Warren commission. He disappeared in a plane crash in October 1972. Commission member Richard Russell told the
Washington Post in 1970 that Kennedy had been the victim of a conspiracy, criticizing the commission's no-conspiracy finding and saying "we weren't told the truth about Oswald".
John Sherman Cooper also considered the ballistic findings to be "unconvincing". Russell also particularly rejected
Arlen Specter's "single bullet" theory, and he asked Earl Warren to indicate his disagreement in a footnote, which the chairman of the commission refused. == Other investigations ==