Experimental Study
Surgery, Gynecology & Obstetrics - February, 1976, Vol. 142, 246-254
The Book Shelf
An Experimental Study of the Backward Movement of President Kennedy's Head
John K. Lattimer, M.D., F.A.C.S., Jon Lattimer, B.A., and
Gary Lattimer, B.A., New York, New York
Attention has once again been drawn to the Warren Commission Report by its critics concurrent with the first publicly televised showing of the Zapruder motion picture of the shooting of President Kennedy before national audiences in 1975. Special attention has been focused on the backward movement of President Kennedy's head and body, which starts one frame (4) after his head was driven forward by a bullet coming from behind and a jet of brain tissue left his head, traveling up and toward the front of the car (3). The sudden subsequent backward and sideways lurch of his body was shown over and over (4), accompanied by insistent, repetitious statements that his backward lurch proved that the President's head was hit by a second bullet coming from the front or right-front of the Presidential automobile.
After this statement was repeated several times,an emotional plea was made by the announcer to reopen the investigation of President Kennedy's shooting on the basis of this so-called proof of an additional assassin's bullet, namely, the backward motion of his head after the initial forward motion.
It was the purpose of this study first to examine whether the backward motion of the head and body might have been due to reasons other than an additional bullet striking the President from the front or right-front and second to re-examine any evidence which might be relevant to the possibility of a bullet having struck the President's head from the front or right-front, based on our previous examinations of the President's autopsy photographs and roentgenograms of his body (11).
To study these problems, the experiments and theories of Alvarez and his associates (1) and Hanson (6) were reviewed, the Zapruder movie was again reviewed in detail and new experiments were conducted, using materials like those at Dallas.
Possible Reasons for the Backward and Sideways Lurch of the President after he was Shot in the Back of the Head
Was it due to the abrupt acceleration of the automobile?
The answer to this question is clearly no!
The acceleration of the automobile was not a factor in the backward lurch, because the automobile did not accelerate abruptly until many frames after the ones in question (4).
(Figure N/A)
Fig. 1. Duplication of President Kennedy's skull wound, produced by a 6.5 millimeter Mannlicher-Carcano fully jacketed military bullet, striking at same point and at same angle as the one which struck the President. The wound of entry is cone-shaped, and the calvarium has burst into many fragments, with the front segments flying so far they were not recovered.
(Figure N/A)
Fig. 2. Roentgenogram of the skull shown in Figure 1. Part of the bullet (Fig. 5), deformed by striking this skull, is shown in the upper right corner of the photograph.
Could it have been partly due to a jet engine effect from the heavy brain material leaving the front of the head with explosive force? The answer to this question is clearly yes!
Doctor Luis Alvarez, of the Department of Physics of the University of California at Berkeley,postulated that the explosive escape of heavy semi-liquid brain material through a large wound of exit in the front of the head must have the propulsive effect of a jet engine, immediately driving the remainder of the head backward toward the rear of the automobile, toward the shooter. In co-operation with Sharon Buckingham, Paul Hoch and Don Olson, he undertook an experiment using melons about the size of a human head, wrapped with two layers of tough adhesive tape, containing strong fibers, to simulate the scalp. These were set upon stands or suspended by straps of tape and fired into while being photographed from the side with a Super 8® motion picture camera using a remote control apparatus. Alvarez permitted us to see the results which dramatically confirmed his assumption. While a small jet of liquefied melon contents escaped from a small wound of entrance,a large mass of heavy, liquefied Melon pulp jetted out the far side, through a large wound of exit. It immediately pushed the melons forcibly backward off the stand and caused the suspended melons to revolve so violently backward and upward around the point of suspension as to tear them completely loose from the restraints. Shots through melons not wrapped with tough layers of simulated scalp did not have this effect. The results of Alvarez's experiments have been published (1).
Melon Experiments Repeated and Extended
In reviewing these experiments, it became obvious that, because of the logistic problems in procuring and testing high-powered military ordnance which is not readily available, there were some aspects of these tests which needed to be repeated and extended, especially if, as seemed likely, they might be regarded as relevant to the backward motion of President Kennedy's head after he was shot. First of all, the rifle, used by Alvarez and his colleagues, used .30 caliber 30-06 cartridges with an extra load so as to have a muzzle velocity of 3,000 feet per second, and the bullets used were the expanding-type, soft-nosed hunting variety. By contrast, we know that President Kennedy was hit by 6.5 millimeter bullets of only about 2,000 feet per second muzzle velocities and that two of the bullets which were recovered and presented by the Warren Commission had intact jackets and were indeed fully jacketed military bullets, rather than soft-nosed expanding bullets (2, 23). The theoretic possibility does exist that the shooter of President Kennedy might have slightly mutilated the noses of the other two bullets fired so that their jackets would open and these bullets might then have acted as soft-nosed expanding bullets after all, although there is actually no evidence to support this theory.
In any case, it seemed worth-while to repeat Alvarez's experiments, using fully jacketed Mannlicher-Carcano 6.5 millimeter cartridges made by the Western Cartridge Company, as at Dallas, and to use not only melons but skull components and combinations of melons and skull components to find out whether the reactions of the simulate heads would then be the same as those demonstrated by Alvarez and his group.
Oswald-Type Carbine Used
In April 1975, a series of experiments was conducted by the authors, using a Mannlicher-Carcano 6.5 carbine of the model 91-38, serial No C2766, equipped with an Ordnance Optics Company four-power telescope, mounted exactly as on the rifle, Warren Commission Exhibit No. 139,which was demonstrated unequivocally by the Warren Commission to have been used to fire both bullets recovered from President Kennedy's car or at Parkland Hospital on the afternoon of 22 November 1963 in Dallas. The ammunition used was from lot 6,000 manufactured by the Western Cartridge Company of East Alton, Illinois, and verified as being one of the four lots manufactured at the same time as the ammunition used in the killing of President Kennedy (15).
(Figure N/A)
Fig. 3. a and b, Backward movement of heads. Remnants of heads jump off the stand toward the gun when struck by fully jacketed Carcano bullets exactly where President Kennedy was struck. Explosive jet of heavy semiliquid brain substance escapes in all directions but always somewhat more through large wound of exit on front of skull, producing a jet-engine effect. This drives what is left of the head toward the gun and toward the left, as with President Kennedy. This effect can be seen in both of these examples, from a series of 12, photographed with a movie camera similar to Zapruder's.
All Test Objects Fell Backward, Toward the Gun
When these bullets were fired into wrapped melons, the melons did indeed move backward off the stand, sometimes rocking preliminarily away from the gun. The size of the splash from our melons was not as large nor as violent as in the experiments of Alvarez and his group, possibly due