From Wikipedia
CE 399, the single bullet described in the theory
The single-bullet theory, sometimes known pejoratively as the magic-bullet theory,[1] was introduced by the Warren Commission in its investigation of the assassination of U.S. President John F. Kennedy to explain what happened to the bullet that struck Kennedy in the back and exited through his throat. Given the lack of damage to the presidential limousine consistent with it having been struck by a high-velocity bullet, and the fact that Texas Governor John Connally was wounded and was seated on a jumper seat 1+1⁄2 feet (0.5 meters) in front of and slightly to the left of the president, the Commission concluded they were likely struck by the same bullet.
Generally credited to Warren Commission staffer Arlen Specter[2] (later a United States Senator from Pennsylvania), this theory posits that a single bullet, known as "Warren Commission Exhibit 399" or "CE 399", caused all the wounds to the governor and the non-fatal wounds to the president, which totals up to seven entry/exit wounds in both men.[3]
The theory says that a three-centimeter-long (1.2") copper-jacketed lead-core bullet from a 6.5×52mm Mannlicher–Carcano rifle fired from the sixth floor of the Texas School Book Depository passed through President Kennedy's neck into Governor Connally's chest, went through his right wrist, and embedded itself in Connally's left thigh. If so, this bullet traversed a back brace, 15 layers of clothing, seven layers of skin, and approximately 15 inches (38 cm) of muscle tissue, and pulverized 4 inches (10 cm) of Connally's rib, and shattered his radius bone. The bullet was found on a gurney in the corridor at Parkland Memorial Hospital after the assassination. The Warren Commission found that this gurney was the one that had carried Governor Connally.[4]
In its final conclusion, the Warren Commission found "persuasive evidence from the experts" that a single bullet caused President Kennedy's throat wound, and all of the wounds found in Governor Connally.[5] It acknowledged that there was a "difference of opinion" among members of the Commission "as to this probability", but stated that the theory was not essential to its conclusions and that all members had no doubt that all shots were fired from the sixth-floor window of the Depository building.
Most critics believe that the single-bullet theory is essential to the Warren Commission's conclusion that Lee Harvey Oswald acted alone.[6] The reason for this is timing: if, as the Warren Commission found, President Kennedy was wounded some time between frames 210 and 225 of the Zapruder film,[7] and Governor Connally was wounded in the back/chest no later than frame 240,[8] there would not have been enough time between the wounding of the two men for Oswald to have fired two shots from his bolt-action rifle. FBI marksmen, who test-fired the rifle for the Warren Commission, concluded that the "minimum time for getting off two successive well-aimed shots on the rifle is approximately 2 and a quarter seconds", or 41 to 42 Zapruder frames.[9][10]
The United States House Select Committee on Assassinations published their report in 1979 stating that their "forensic pathology panel's conclusions were consistent with the so-called single bullet theory advanced by the Warren Commission".[11]
Origin
The first preliminary report on the assassination, issued by the FBI on December 9, 1963, said: "Three shots rang out. Two bullets struck President Kennedy, and one wounded Governor Connally."[12] After the report was written, the FBI received the official autopsy report which indicated that the bullet that struck the president in the back had exited through his throat.[13] The FBI had written their report partly based on an initial autopsy report written by their agents[14] which reflected the early presumption that that bullet had only penetrated several inches into the president's back and had likely fallen out. The FBI concluded, therefore, that the governor had been struck by a separate bullet.[15]
The Warren Commission commenced study of the Zapruder film, the only known film to capture the entire assassination sequence, on January 27, 1964.[16] By then, the FBI had determined that the running speed of Abraham Zapruder's camera was 18.3 frames per second,[17] and that the Mannlicher–Carcano rifle found at the Texas School Book Depository, the presumed murder weapon, could not be fired twice in less than 2.3 seconds,[18] or 42 frames of the Zapruder film.[16]
When the Commission requested and received after February 25 higher-resolution images of the Zapruder film from Life magazine (who had purchased the film from Zapruder), it was immediately apparent that there was a timing problem with the FBI's conclusion that three bullets had found their mark.[19] Kennedy was observed by the Commission to be waving to the crowd at frame 205 of the Zapruder film as he disappears behind the Stemmons Freeway sign, and seems to be reacting to a shot as he emerges from behind the sign a little more than a second later at frames 225 and 226. In their initial viewing of the film, Connally seemed to be reacting to being struck between frames 235 and 240.[20]
Given the earliest possible frame at which Kennedy could have been struck (frame 205), and the minimum 42 frames (2.3 seconds) required between shots, there seemed to be insufficient time for separate bullets to be fired from the rifle. Several assistant counsels, upon viewing the film for the first time, concluded there had to be two assassins.[21]
On April 14 and 21, two conferences were held at the Commission to determine when, exactly, the president and governor were struck. Assistant counsel Melvin Eisenberg wrote in a memorandum dated April 22 on the first conference that the consensus of those attending was, among other issues, that Kennedy was struck by frames 225–6 and that "the velocity of the first bullet [which struck Kennedy] would have been little diminished by its passage through the President. Therefore, if Governor Connally was in the path of the bullet it would have struck him and caused the wounds he sustained in his chest cavity... Strong indications that this occurred are provided by the facts that... if the first bullet did not strike Governor Connally, it should have ripped up the car but it apparently did not." However, the memorandum stated, given the relatively undamaged condition of the bullet presumed to have done this, CE 399, the consensus was a separate bullet probably struck his wrist and thigh. While not specifying a precise frame for when it was thought Connally was struck by the same bullet which struck Kennedy, the consensus was "by Z235" as afterwards his body position would not have allowed his back to be struck the way it was.[22]
By the end of April 1964, the Commission had its working theory, the single-bullet theory, to account for the apparent timing discrepancies found in the Zapruder film and the lack of any damage to the limousine from a high-velocity bullet exiting the president's throat.[23] (Impact damage was observed in the limousine, but was indicative of lower-velocity bullets or bullet fragments. For example, a nick on the limousine's chrome was not from a high-velocity bullet as such a bullet would have pierced the chrome, not merely dented it.)[24]
On May 24, the FBI and Secret Service reenacted the shooting in Dallas and the Commission tested its theory.
