HEAR NO EVIL
THE ACOUSTICAL EVIDENCE IN THE KENNEDY ASSASSINATION
Dr. Donald B. Thomas
November 17, 2001
In 1978 the House Select Committee on Assassinations was presented with acoustical evidence that multiple shooters had been involved in the murder of President John F. Kennedy. During the hearing, staff members played a tape recording for the Committee with the explanation that they were about to hear a rifle shot fired from the Grassy Knoll. After listening to this tape the ranking Republican member of the Committee, Representative Samuel Devine of Ohio, rose in the chamber to declare that he had a great deal of experience with firearms and familiarity with rifle fire. He knew a gunshot when he heard one, he said, and the sound alleged to be from the Grassy Knoll could be many things, but it was clearly not a rifle shot. The staff then explained to Mr. Devine that the tape recording was of a test shot fired from the Grassy Knoll that summer; not the Dallas Police tape from 1963. The incident suggests two things. First, that one cannot determine that a recorded sound is or is not gunfire merely by listening with the naked ear. Secondly, it suggests that Congressman Devine may not have been completely open-minded to the concept under investigation by his Committee.
Over the last year I have discovered that there are others who are less than receptive to this evidence. While experiencing my fifteen minutes back in March, appearing on television and radio, the producer for ABC's Nightline program asked me if I realized that the article I had published (in the British forensic journal Science & Justice) had made a lot of people very angry. I said that, yes, I understood that. He then remarked that, on the other hand, I had undoubtedly made a lot of conspiracy buffs very happy. "Well, no, not really," I said. The acoustic evidence does contradict the official version of events which holds that there was no more and no less than exactly three shots. But, I explained, most conspiracy buffs are convinced that JFK received at the very least, a frontal shot through the throat, and another through the head as well. The acoustical evidence indicates only one shot from the front. Moreover, when one synchronizes the acoustical evidence with the filmed evidence, the shot from the front aligns with the head shot. The lack of evidence for a frontal shot for the throat wound tends to support the single bullet theory, and the single bullet theory is anathema to most conspiracy buffs.
The producer told me that in journalism, when those on opposite sides of an issue are both unhappy with the reporting, they like to think that they are probably doing something right. I am not sure that this is a perfect analogy, but the point is that, as I stand before you today, I am perfectly well aware that many if not most of you are not yet convinced by this evidence. And I hasten to add that I am not going to try to convince you. I have a good friend who teaches Biology at a college in Georgia, a course which includes instruction in Evolution. Naturally, his students include many who are devoutly religious. He tells them, what I wish to tell you now. I don't care what you believe, but, I do care that you know the facts.
When I first wrote my article on the acoustics, I submitted it to the Journal of Forensic Science here in the United States for publication. The editor kicked it back, stating that it was their editorial policy not to publish articles on the Kennedy assassination. He defended this policy on the grounds that no amount of reanalysis was going to change anyone's mind. As one who routinely reviews scientific articles for publication, I must say that this seemed like an odd position for a scientist to take. And I reiterate that I am not trying to change anyone's mind. My mission is to present the facts and let people make up their own mind. Having said that, I am going to avoid as much as possible making an overly technical presentation of the acoustical evidence today. The reports of the acoustics studies are available in the HSCA proceedings if anyone needs those details. Rather, in my talk today I am going to address the criticisms of the acoustical evidence that have been brought to my attention, and to show how the acoustical evidence meshes with the other crime scene evidence, particularly the Zapruder film.
One of the criticisms that I have been personally subjected to was brought up, among other places, on the Fox Morning News program. The host of that show said, "You're just an entomologist, why should anyone believe you?" Now you should understand that these shows are rehearsed. The producer of the program likes to know ahead of time what the guest is going to say, in part so they have interesting discussion, and in part so the host doesn't look stupid. So I knew the question was going to be asked. I was tempted to say that, "No, I am not an acoustical expert, but I did stay in a Holiday Inn last night." Instead I pointed out that even an entomologist knows that a scientific hypothesis stands or falls on the evidence behind it and not on the status of the person who makes it. I might also have pointed out that if expertise were the issue -- then I win.
When the House Select Committee on Assassinations was first confronted with this evidence, they asked the Acoustical Society of America for a short list of the top acoustics laboratories in this country. At the top of the list was the expert consulting firm of Bolt, Baranek & Newman (BBN)of Cambridge, Massachusettes. They had done the Watergate tapes for the Ervin Committee and the acoustics study of the Kent State shooting for the Department of Justice. These experts determined that the assassination gunfire was on the Dallas police tapes and they were the experts who found the "fingerprint" of a gunshot from the Grassy Knoll.
Because that finding was politically incorrect, and because there was an element of uncertainty with regard to the alleged grassy knoll shot, a second expert opinion was sought. Back to the short list, the next laboratory was the Computer Science Department of Queens College, New York, where Professor Mark Weiss and his assistant Arnold Aschkenasy wrote computer programs with sonar applications for the military. They had also published on methods for detecting and separating real sounds from noisy backgrounds. Using the principles of sonar analysis (echo location) they eliminated the cause of the uncertainty and concurred that there was scientific evidence of a shot from the Grassy Knoll on the police tapes.
So, if expertise is what one requires, the top acoustic experts agree that there was scientifically valid evidence for a shot from the Grassy Knoll. Moreover, there has never been a direct challenge to the acoustical evidence, or its analysis, or the methods which were used to determine that shots were present on the police tapes.
What about the FBI report? A report by the FBI is sometimes cited as an expert refutation of the acoustical evidence and I have been been criticized for ignoring the FBI report, which indeed I did. The criticisms raised in the FBI report, published in two installments of the Law Enforcement Bulletin in November and December 1983, have no scientific validity. The article was written by Special Agent Bruce E. Koenig of the Technical Services Division, a forensic expert with the Signal Analysis unit. Given a chance to present these criticisms to a joint meeting of the NRC panel and the HSCA committee's experts, most present agreed that the FBI's arguments were "irrelevant." More to the point, they were an embarrassment.
The FBI report states that Weiss and Aschkenasy had testified that they had identified the gunshot from the Grassy Knoll on the basis of the supersonic shock wave and the muzzle blast impulse. In point of fact, neither Weiss nor Aschkenasy (nor anyone else) ever made any such statement in their testimony (or their reports). Moreover, Koenig added,
"It is not known which characteristic Weiss and Aschkenasy actually used in their analysis."
Weiss and Aschkenasy had relied on neither the muzzle blast nor the shock wave in concluding that there was valid evidence for a gunshot from the Grassy Knoll. Weiss and Aschkenasy's conclusions were based on echo correlation. That is, on the high degree of match between the echo delay pattern of recorded test shots and an impulse pattern on the police evidence tape. Koenig never did explain in his articles that Weiss and Aschkenasy had used echo location to determine that there was a Grassy Knoll gunshot, nor the methods by which BBN had identified the suspect noise in the first place. These omissions prevented the reader from knowing the actual data and logic behind the conclusions of the acoustics experts.
Preliminary screening of the police tapes by the BBN lab led to the identification of five impulse patterns that were considered as candidate gunshots because they had some of the acoustic characteristics of gunfire. These suspect noises occurred together in a cluster about two minutes into the open microphone segment. All five suspect patterns were found to match test shots fired in Dealey Plaza, and all five were ultimately identified as gunshot patterns by the experts. I realize that this fact is widely misunderstood. But no one misunderstood the analysis as badly as the FBI. The FBI critique states that six impulse patterns were rejected by the BBN analysis, either because they were inconsistent with the motorcycle position, or, they were inconsistent with the target location [Koenig 52(12):5]. This statement was completely divorced from reality. BBN had rejected six mathematical correlations to test shots on those grounds, but no evidence patterns were rejected because they were inconsistent with the motorcycle position or the target location. This misstatement by the FBI is particularly prejudicial because it would lead a reader to conclude that there were many other candidate impulse patterns on the police tape besides the ones alleged to be gunshots.
The FBI report complained that the patterns should not have been judged as matches because,
"...tests performed by BBN on a radio system similar to that used by the DPD showed considerable distortion of loud impulsive sounds such as gunshots, which resulted in the elimination of impulse peaks, change in the position of peaks, and even the production of new peaks where no impulse peaks previously existed."
If one compares these two oscillographs (Figure 1) it can be seen that just as the FBI complained, they don't look anything alike. The graph on top is the echo pattern of a test shot fired from the Grassy Knoll. Below is an impulse pattern found on the police tape. The Dallas police recording was not a high fidelity record. The automatic gain control and limiting circuitry does distort the amplitude and waveform of loud impulses. But, it was absolutely essential to the understanding of the acoustical matching procedure that impulses were not moved or eliminated, nor were impulses produced where none had existed. Without that fundamental understanding it would be impossible to comprehend the analyses that were conducted on the DPD recording by BBN and Weiss and Aschkenasy, and exactly why the FBI opinion was invalid. Koenig missed, misunderstood, or ignored the following statement in the Assassination Committee's report,
"The time of the arrival of the impulses or echoes, in each sequence of impulses was the characteristic being compared, not the shape, amplitude or any other characteristic of the impulses or sequence."
[HSCA Final Report p. 70].
I have to admit that my reaction to reading the FBI report was one of anger. I felt that the FBI report was prejudicial and dishonest. I now realize that the FBI report was the product of incompetence. In that FBI report Mr. Koening cited as evidence of his expertise in acoustical principles, his work on the case known as the "Commie-Klan shootout." Koenig was indeed called as an expert witness in this case in which the Ku Klux Klan had been given a permit to march in Greensboro, South Carolina. The Communist Workers Party arranged for a counter-demonstration, attracting members of the Nazi party, and anticipating trouble, some had brought weapons. Trouble did ensue, fighting broke out and several persons were shot dead. Koenig was asked to use acoustical principles to determine who had fired the first shot.
An account of the trial can be found in the textbook "The Acoustics of Crime," by a real acoustics expert, Professor Harry Hollien of the University of Florida, who was also consulted during the case. He recounts,
"...a government agent testified that he used the sounds of the gunfire (recorded by several television crews) and the known reflective surfaces of the environment to identify the source of the gunfire. From these data, it was concluded that the communists had shot first. The Klan members were acquitted of murder. However, during the second trial (involving violation of civil liberties), the agent indicated that he had recalculated his measurements and now believed that it was the Klan members who had first opened fire. Obviously,this reversal in position resulted in some confusion and I was asked to reanalyze the data."
[Hollien pp. 310].
Hollien's investigation revealed that Koenig had based his analysis on the wrong microphone location. (In case you are wondering, Hollien subsequently determined that a communist had shot first) [Hollien p 311]. This criticism of Koenig is not just an ad hominem argument. Koenig specifically cited his performance in the Commie-Klan Shootout as evidence of his expertise [Koenig 52(11):2]. The truth suggests that Koenig's performance was less astute than his article had asserted.
Koenig has also asserted that his work in the Commie-Klan Shootout was the first instance that acoustical principles had been used to identify a shooter in a criminal case. This is not so. The first such case was the Kent State shooting. That case was worked by BBN's lead scientist, James Barger. And in that case, it should be noted, that using the exact same procedure - echo location - and the audio record of the incident, Barger had identified the physical locations to within ten feet of where the first several gunshots were fired. Using photographs and films of the incident, the Department of Justice identified the individual National Guardsmen in those specific locations. When these men were arrested - all admitted that they had fired their weapons.
I mention this evidence for the benefit of those who cite the claim of the NRC panel that this technology is unproven. Although its use in criminology is somewhat novel, the same technology had been used for many years by the army for locating enemy gun emplacements, by the Navy to navigate underwater, and by geologists searching for oil.
I should now clarify an issue which I earlier stated is widely misunderstood, and that is with regard to the number of candidate sounds examined and the number determined to be shots. By preliminary studies in the laboratory, BBN identified six segments of tape which contained impulse patterns which had the acoustical characteristics of gunfire and which were then subjected to echo correlation analysis. But, one of the six evidence patterns was included even though it had failed to pass the preliminary screening tests. It failed because it did not have as many impulses (putative echoes) as the other patterns. It was included primarily because it was in close proximity to the other candidates, a sort of guilt by association. Secondly, BBN wanted to test the supposition that a gun fired with the barrel withdrawn inside the window of a building might be attenuated, and thus have fewer impulses (echoes) than a shot fired with the muzzle outside. Ultimately, this test failed and the pattern was rejected (again). All of the five segments of tape identified in the preliminary screening tests had patterns which matched to test shots. The ultimate conclusion of the HSCA Committee was that there was evidence for only four shots (only?). It should be clarified that the acoustics experts employed by the HSCA never came out and stated boldly that there were any particular number of shots. In fact, those of you familiar with his testimony know that Dr. Barger went to great pains to resist making any such final conclusion for the Committee. Rather, he insisted that it was up to the committee to decide if any of the sounds really were assassination gunshots, and that such a conclusion should be made by those with access to all of the evidence, including the acoustical evidence.
I endorse that sentiment whole-heartedly, and the object of my lecture today is to show that the non-acoustical evidence is in close accord with the acoustical evidence and for that reason it would be perverse to insist that the assassination gunshots are not on the police tape. Moreover, in spite of the Assassinations Committee's finding, BBN had found acoustical evidence for five shots. That is because five evidence patterns had matched to the echo patterns of test shots. The reduction from five to four in the final report was made not because of acoustical evidence but because of a perversion of the non-acoustical evidence.
In detection theory one has to allow for false alarms. It is reasoned that because acoustical principles were used to make the detections, only non-acoustical evidence should be used to judge whether a detection is true or false. In this instance unreliable non-acoustic evidence and the non-expert advice of the Committee's Chief Counsel resulted in the judgment that one match was a false alarm. Oswald's rifle could not be fired in less than 2.25 sec. The problem was that the sound in question occurred too close to the previous sound identified as a shot, only 1.1 sec, and thus, inasmuch as both could not have been fired from the Book Depository rifle, the latter was judged a false alarm [8 HSCA 65]. This reasoning was tantamount to saying that if Oswald didn't fire it, it wasn't a shot. Logically, the same reasoning should have been applied to the spacing between the first two putative shots (1.6 sec). When the weapons testing evidence is applied objectively, the shot that should have been identified, as the rogue shot was the second, not the third. But the second could not be reasonably dismissed as a false alarm because four test matches were achieved. I have consulted with Professor G. Robert Blakey, the former chief counsel for the Assassinations Committee, and Dr. Barger on this issue. Evidently there was a misguided perception that the Committee members might be more easily convinced of the acoustics evidence if there were not a rogue shot. Dr. Barger admitted to me that the criteria for judging a "false alarm" in this instance was "ad hoc," -- which is Latin for "bull-oney." Some matches were judged to be false alarms because it would require an unrealistic microphone trajectory. That is not the case for the third noise. On the contrary, it falls exactly into the order required by the working hypothesis.
THE ORDER IN THE EVIDENCE
For those who would hear no evil, the matching of the test shots to the sounds on the police tape is dismissed as a case of random noises which by chance happened to resemble gunshots. Yes, it could happen. Perhaps there was a solar flare just eight minutes before the President turned on to Elm Street and a burst of electromagnetic radiation struck the police radio system giving rise to static clusters that resembled three shots from the book depository, one from the Grassy Knoll, and another from one of the buildings behind the President. My article in S&J provides a formal statistical calculation against that probability. For the sake of argument, let us suppose that there were extenuating circumstances that are beyond our present knowledge and the finite probability was actually reasonably high. Even so, if the evidentiary and test patterns had no real commonality and the matches were entirely spurious, then matches would occur at any of the 36 microphone locations,
and in no particular order. But they occurred in exactly the right order. That is, if we number the noises on the police evidence tape in chronological order, 1-2-3-4-5, the matches were found at microphones that line up along the path of the motorcade in the same 1-2-3-4-5 order. There are 125 ways to order five numbers, all of which have an equal chance of occurring and only one of which is, 1-2-3-4-5.
The similarity in the spacing is also remarkable. The spacing between the noises on the police tape is: 1.6, 1.1, 4.8 and 0.7 seconds. The array of test microphones were set at 18 foot spacings (Fig. 2). The first three matches were found at three consecutive microphones on Houston Street. The last two matches were found at two consecutive microphones on Elm Street. The distance between the third and fourth matching microphones was 72 feet. Thus, the spacing between the microphones is a close match to the spacing of the noises on the police evidence tape. Moreover, the distance from the first matching microphone location (no. 5 of array 2) to the last (no. 5 at array 3) was 143 feet. The time separating the first and last shot was 8.3 seconds. For a motorcycle to travel 143 feet in 8.3 seconds its trajectory would have to be 17.2 feet per second; equivalent to 11.7 mph. This is an impressive coincidence when one compares it to the FBI's reconstruction in 1963 which estimated that the President's limousine was traveling at an average speed of 11.3 mph on Elm Street. Thus, the topographic order in the matching data is in remarkably close accord with the working hypothesis that a police motorcycle with an open microphone was traveling in the motorcade, northerly on Houston Street and westerly on Elm Street at a speed of around 11 mph when the President was killed by gunfire. That seems like a lot to ask of sunspots. It was this order in the data that caused the acoustics experts to conclude that there was valid scientific evidence that the assassination gunfire had been captured on the police tapes.
FILMED EVIDENCE OF THE MOTORCYCLE.
The obvious procedure to follow at this point is to examine the newsreels and photographs of the Presidential motorcade in Dealey Plaza to see if there was a motorcycle in the location predicted by the acoustical evidence, and if there was, did that motorcycle have a sticky microphone relay switch. Some of you already know the answer to that question. Richard Trask's otherwise excellent book, "Pictures of the Pain," states that there was not. So let us clarify the record.
If there is any validity to the acoustical evidence then there had to have been a police motorcycle with an open microphone in the vicinity of the intersection of Elm and Houston during the assassination. More precisely, the open microphone had to have been on Elm Street 141 feet behind the President when an assassin fired from the Grassy Knoll, if one infers, as I do, that the Grassy Knoll shot was the fatal shot. Our chronograph of the assassination is the Zapruder film. So we begin our analysis by synchronizing the putative shots to specific frames in the Zapruder film. This synchronization is shown in Table 1.
Table 1.- Synchronization of Putative Shots to Zapruder Frames
ACOUSTIC TAPE TAPE-TIME REAL Z-FRAME SHOT
EVENT TIME INTERVAL TIME EQUIVALENT ORIGIN
A 136.2 - 8.7 9.1 Z - 147 No Match
B 137.7 - 7.2 7.5 Z - 175 TSBD
C 139.2 - 5.6 5.8 Z - 204 Rogue Shot
D 140.3 - 4.6 4.8 Z - 224 TSBD
E (145.1) 144.9 0 0 Z - 312 KNOLL
F 145.6 + 0.7 0.7 Z - 326 TSBD
Tape Times from BBN Report Table 2.
Event E time correction at 8 HSCA 115.
Tape speed correction factor 1.043 [8 HSCA 27].
Zapruder Film speed 18.3 fps.
In the mid-section of the motorcade there were four motorcycle patrolmen: Marion Baker, Clyde Haygood, J.W. Courson and H.B. "Buddy" McLain. Of these, Baker and Haygood stopped to search for the assassins in Dealey Plaza. Because the motorcycle motor noise on the police tape does not stop, only Courson and McLain are viable candidates for the source of the broadcast, if the broadcast originated in Dealey Plaza. In testimony to the House Select Committee on Assassinations, McLain acknowledged that he had a chronic problem with a faulty microphone relay on his unit that caused it to stick open from time to time.
This photograph (Fig 4) taken by Wilma Bond, shows McLain and Courson on Elm Street in front of the Grassy Knoll where patrolman Bobby Hargis had stopped to search for the assassin. Hargis' motorcycle was parked on the south of the sixth pair of roadstripes from the intersection at Houston Street, just beyond where President Kennedy received the fatal shot. According to Richard Trask [p. 208] the Bond Photo was taken "within 20 sec" of the shooting. However, the scene has to happen later than that. A discontinuous film taken by Mark Bell also shows McLain and Courson passing Hargis. But an earlier sequence shows a witness in the background named Charles Hester rising from the ground. At the sound of gunfire Hester had pushed his wife to the ground and covered her body with his own. Hester is seen standing up in other films, in particular, a newsreel shot by Dave Wiegman. Wiegman's film is a clock because it can be connected to the pivotal Zapruder film. A brief instant of the Wiegman film shows the President's limousine approaching the underpass. In the Zapruder film, the President's limousine arrived at the underpass at frame 463, which is 8.2 sec after the head shot. The Wiegman film is 27.3 sec long and the frames showing the limousine approaching the underpass appear 11 sec into the film. Therefore, the Wiegman film begins no later than about 3 sec before the head shot. Towards the end of the film, at sec 26, Hester is seen rising from the ground. Because the frame in the Wiegmann film showing the limousine can occur no later than 8 sec after the head shot, Hester must have stood up no later than 23 sec after the President was shot in the head. Assuming that Bell stopped for about 4-5 sec, allows us to estimate that McLain reached the position shown in the Bond photo at around 27 sec after the head shot.
This map (Fig. 5), uses the acoustic evidence coupled with the aforementioned film evidence, to plot a trajectory for McLain's motorcycle through Dealey Plaza at the time of the assassination. Point (c) is McLain's position as seen in the Bond photo. Point (b) is the acoustically determined position of the motorcycle at the time of the Grassy Knoll shot. It is defined as 97 ft south of the TSBD and 27 ft east of the south west corner of that same building [8 HSCA 28]. The path of the motorcycle is shown in the south lane of Elm Street because the films show McLain there. From point (b) to point (c) the plotted trajectory would require McLain to idle at about 4 mph. This is consistent with the police tape which indicates that the motorcycle idled for about 30 sec after the last shot [5 HSCA 714].
The five circles represent the 18 ft radii of the microphone positions that recorded test shots that matched impulse patterns on the Dallas Police tape. The acoustical reconstruction requires that the motorcycle passed through each of these circles in succession. This distance, from first to last, is 143 feet, and the time lapse was 8.3 seconds. This required a velocity of approx. 11 mph during this sequence.
Point (a) on this map corresponds to McLain's position as seen in a 5 sec film sequence taken by Robert Hughes, the last sequence shot by Hughes prior to the assassination. Hughes wrote in a letter to his parents,
"About five seconds after I quit taking pictures we heard the shots..."
[Trask p. 265].
The frame showing McLain (Fig. 6-see bottom) is the 20th frame of the sequence, and thus occurs four sec before the end of the film. Added to Hughes' five sec estimate places the frame nine sec before the first shot. I have estimated the time to be closer to six or seven sec before the first shot. The audio record shows the sound of the motorcycle motor at a constant level until 3 sec before the first putative shot, when the motor noise drops to one fourth of that level [8 HSCA 11]. This requires the motorcycle to travel at a faster speed prior to the shots than during or after the shots. By setting H-20 at 6-7 sec prior to the first shot a trajectory of about 20 mph is projected for McLain's motorcycle on Houston Street. This speed is about twice the speed of the motorcade itself and is required because at this time, the President's limousine has already turned on to Elm Street, 220 ft away. Recall that the acoustically defined position at the time of the head shot is only 141 ft behind the limousine, thus, McLain has some ground to make up.
The proposed trajectory forms a hypothesis which is subject to testing. There have been assertions that films and photographs prove that McLain was not or could not have been in the acoustically predicted locations. One of the challenges which has appeared on the internet is the assertion that the Hughes film proves McLain to have been in the wrong place at the wrong time. The basis for this claim is the angle of the car at the head of the column of cars seen on Houston Street in H-20. This car, a yellow mercury hardtop, is the fifth car in the motorcade, and contains a secret service contingent attached to the vice president, who was in the fourth car of the motorcade. One can clearly see that this car has pulled out of line and is starting its turn on to Elm Street.
According to the critics, this action corresponds to frame 160 of the Zapruder film. This map (Fig. 7), is a plot of the position of the cars seen at the intersection of Elm and Houston at frame 160. If this interpretation is correct; that it corresponds exactly or even closely to H-20, then McLain cannot possibly be in the locations required by the acoustical evidence because Z-frame 160 synchronizes to less than one sec before the first shot (at Z-175). McLain would have to travel about 180 feet in less than one sec, requiring a velocity of 140 mph.
But this interpretation is probably not correct. An important factor in this analysis is the speed of the motorcade. One can measure the speed of the cars by counting the number of frames it takes for the vehicle to pass objects in the background. In this case, Car-5 can be seen passing a lady in red from Z-frames 144 to 180. That is, it required 36 frames, or 2 sec, to travel its own length which was about 16 ft. This calculates to a speed of only 5.5 mph. This means that a small error in the car's position can mean a big error in the estimated time lapse between events.
On this map (Fig. 8) I have plotted an alternative interpretation of the car positions seen in H-20. This interpretation suggests that Car-5 began its turn prior to the point where it came into view of Zapruder's lens, and then because of the sharpness of the turn, had to make a second steering adjustment while in the intersection that is seen in the Zapruder film. The question is, which of these two interpretations is more likely to be correct. I would argue that a connection between the Hughes film and the Zapruder film can be made more accurately by relying on the cars closer to Hughes, because their position is less equivocal than the one farthest away. Such a car is car No. 8.
This map (Fig. 9) plots the positions of Car-8 as seen in the Zapruder film and as it is seen in the Hughes film. We can plot its position in the Zapruder film exactly, because it comes into alignment with an oak tree between Zapruder and Houston Street at frame 220. Moreover, we can measure the velocity of this car in the same manner that we measured that of Car-5, by measuring its change in position relative to stationary objects. In this instance it required 21 Z-frames to travel its own length. Because Car-8 is a two-door Chevrolet Impala its chassis length was 15 ft (180 inches according to the 1964 Chilton's manual). Its speed thus calculates to 8.5 mph (=12.5 ft/sec). The difference in speed between Cars-8 and -5 is understandable because the turns through Dealey Plaza were causing an accordion effect, such that the cars would bunch and slow down through the intersections, but then on leaving the intersection, space would open and the cars could speed up on the straight-aways.
The distance between Car-8's measured position at Z-220 and its estimated position at H-20 is 88 feet. At a speed of 12.5 ft/sec, the car would need 7 sec to cover the distance. At 18.3 frames per sec, H-20 would be equivalent to Z-90, not Z-160. This would place McLain's position at the Main Street intersection about 4.6 sec prior to the first shot. But, if one factors in the accordion effect, Car-8 was probably averaging between 6-8 mph and thus McLain's position in H-20 is likely closer to six to seven sec prior to the first shot, in accord with Hughes memory that the shots occurred several seconds after he stopped filming.
Another mistaken assertion that filmed evidence discounts the acoustical evidence, traces back to the days of the Assassinations Committee. The Committee published a frame from the Dorman film showing a motorcycle officer at the corner of Elm and Houston which was supposed to be officer McLain. To the officer's right was an automobile asserted to be Car Number 8 and it was further asserted that this time and location was coincident with the predictions of the acoustical evidence. Both assertions were wrong. In the first place, in order to be in the right place, McLain should have rounded the corner in the proximity of Car-6. It was subsequently realized that the automobile partially visible in the Dorman film was actually the eleventh car in the motorcade and this places the motorcycle well back of where it must be to have the microphone that recorded the assassination gunfire.
But the officer in the Dorman film is not McLain; it is Clyde Haygood. This can be seen by examination of the newsreel footage taken by Malcolm Couch. This still (Fig 10) is a frame from this newsreel, which from context we can see was taken a few seconds before the Bond photo. Couch's film shows all four of the motorcycle patrolmen at the mid-section of the motorcade. In this single frame we can see three. McLain is way in the distance approaching Hargis's parked motorcycle, Courson is about half way to McLain, and here is Haygood. In the running film one can see Haygood passing Couch on the left. Couch was in the tenth car of the motorcade. To orient the situation I have prepared this plot of the vehicle positions (Fig. 11). Car-10 is at the first road stripe on Elm Street when it was passed by Haygood. This means that Car-11 is at or near the corner and this means that the sequence seen in Couch immediately follows the sequence seen in the Dorman film where Car-11 is approaching the corner. Therefore the motorcycle officer next to Car-11 in the Dorman film has to be Haygood.
When Officer McLain learned that his testimony to the Assassinations Committee was supportive of evidence that a motorcycle radio had recorded the assassination gunfire, McLain claimed that he had stopped on Houston Street, and that moreover, he claimed that he watched Mrs. Kennedy climb out on to the trunk of the limousine by looking through holes in the reflecting pool wall between himself and the other side of the Plaza. However, McLain's memory is contradicted by the recollections of J.W. Courson. Perhaps unaware of McLain's statements, Courson related to researcher Larry Sneed in "No More Silence," that just as he turned the corner on to Elm Street he saw Mrs. Kennedy out on the trunk of the President's limousine. This event is seen in the Zapruder film about 2-4 sec after the head shot. Thus, Courson must have reached the corner at about the time of the head shot, and because McLain is well ahead of Courson in the Couch film, he must also have been on Elm Street at that time, as projected. The acoustically identified position for the head shot is about 70 ft from the corner. The plotted trajectory of McLain's motorcycle has him arriving at this corner just ahead of Mayor Cabell's car, the sixth car in the motorcade.
Although no other films or photographs show McLain between the Hughes film and the newsreels taken after the shooting, there are films showing portions of Elm Street and Houston Street during this sequence. These at least show us that McLain was not where he was not supposed to be. It is sometimes asserted that McLain should be visible in the Altgens photograph and his absence is cited as evidence that he is not where he should be. Here is the photograph in question (Fig. 12). It is equivalent to Zapruder frame-255. Altgens was about 60 ft in front of the President's limo. Note that the vice-president's car is aligned with a shadow thrown by a tree on the south side of Elm. Most importantly one can see that a portion of Elm Street is missing, although a portion of the south curbside is visible. The field of Altgen's lens-eye view ends to the right at a point on the Dal-Tex building between the Houston Street entrance and the corner of the building. A plot of Dealey Plaza shows this line of sight (Fig. 13) and shows how, based on the proposed trajectory, McLain should be out of sight, to the right and behind the fifth car in the motorcade.
Sequences in the Dorman film show both Car-5 and Car-6 at or near the intersection of Elm and Houston, which is about the time that McLain is predicted to have rounded the corner. Unfortunately, Dorman's film is stop and go. Moreover, her camera had a telephoto lens which greatly narrowed the field of view when she did film Elm Street. In this case, Dorman stopped filming just as the nose of Car-5 entered the last frame of one sequence. When she began filming the next sequence, the view just captures the rear half of Car-6, the Mayor's car, passing to the west. Had she filmed continuously we might have had evidence that McLain was, or wasn't, where he is supposed to have been.
Similarly, it has been alleged that McLain should be visible in the Zapruder film. There is a brief sequence, between frames 175 and 190, about one sec, where the Mayor's car, is undoubtedly in the scope of view, but hidden behind the crowd on the corner of Elm and Houston. McLain should be between the Mayor's car and the crowd, but if he is, he is also hidden from view. Some researchers believe that one object visible in gaps between the bodies is McLain's helmet and another is the wheel of his cycle. I am not convinced one way or the other.
The bottom line is that the film evidence is not definitive with regard to whether McLain was or was not in exactly the right positions required by the acoustical evidence because we simply do not have pictures showing these positions when Mclain is predicted to be there. However, if McLain was in continuous motion between where the motion pictures by Hughes and Couch show him to be, he would have been at least close to the predicted positions - and he did have a sticky microphone relay. In itself that is a remarkable coincidence if the gunshot sounds are nothing more than solar flares.
THE DOUBLE DECKER
Unable to find significant errors in the acoustical analysis, the National Research Council's panel on ballistic acoustics relied on an artifact to raise doubts about the validity of the acoustical evidence. If there was reasonable doubt, then one could argue that the acoustical evidence was not proof that there was a gunshot from the Grassy Knoll. The artifact, actually discovered by researcher Steve Barber and dubbed the Double Decker, suggests that the noises on the police tape might not be synchronous with the time of the shooting.
The evidence for this assertion is a barely audible fragment of garbled speech that occurs at the time of the putative shots on police channel one. The graphic I am showing you now (Fig. 14) depicts the timeline of events that occurred in the minutes immediately following the assassination. The Ch-2 recording shows that Sheriff Decker made a broadcast that included the phrase, "Hold everything secure..." almost exactly one minute after Chief Curry broadcast his order, "Go to the Hospital..." Curry would not have given his order unless he knew there was a medical emergency in the motorcade. Because a portion of the Decker broadcast crossed over to channel one and is essentially simultaneous with the alleged shots, the sounds reputed to be gunshots must actually occur well after the assassination.
But this hypothesis is valid only to the extent that crosstalk can give us an unequivocal synchronization of events recorded on the two channels. Although it is true that alignment of the Decker broadcasts fails to match the putative gunshots to the time of the assassination, in point of fact, matching of the Decker broadcasts fails to align any events on the two channels. Conversely, using any of the other instances of crosstalk between the channels, does align the alleged shots with the time of the shooting. The graphic in Fig. 14 uses the broadcast by Sgt. S.Q. Bellah wherein he said, "You want me to hold traffic on Stemmons." If one uses the Bellah crosstalk to synchronize events on the two channels it can be seen that the gunshot sounds align with a time immediately before Chief Curry says, "Go to the Hospital." This is congruent with Curry's testimony to the Warren Commission that he heard the "first report" and that he made his broadcast, "almost immediately." [4 WCH 161].
The assertion that Curry made his broadcast "almost immediately" following the shots has been criticized on the grounds that Chief Curry would not have known that anyone had been shot so soon after the shooting. In an interview with researcher Gary Mack, Curry recalled that he learned that the President was shot only when the President's limousine and escort caught up with his car at the underpass, an event which is seen in films to have occurred at least 15 sec after the shooting.
However, there is better evidence that establishes an earlier contact. Secret Service Agent Roy Kellerman was in the limousine with the President. That evening at Bethesda Naval Hospital, Kellerman related his experience to FBI agents Siebert and O'Neil, who were detailed to observe the autopsy. Kellerman repeated his story in a formal interview four days later, and in his testimony to the Warren Commission. Kellerman stated that after the first volley of shots he clearly heard the President say in his Bostonian accent, "My God - I'm hit." Kellerman related that he had his microphone in his hand, that he was in radio contact with secret service agent Winston Lawson, sitting next to Curry, the driver of the pilot car, and that he immediately called with orders,
"Lawson, this is Kellerman...We are hit; get us to the hospital immediately. Now in the seconds
that I talked just now, a flurry of shells came into the car."
[2 WCH 73-74].
Kellerman's account of events recorded on the day of the assassination must be given more weight than Curry's recollection of events many years later. One could also argue that the reason that the lead car stopped under the triple underpass and waited for the Limousine and escort was because they already knew that something was wrong. Kellerman's testimony explains why Curry could have made his call so close after the time of the shooting. According to Kellerman's testimony his call to the lead car was made before the shooting was over, not after. Interestingly, although there is no recording of the Secret Service channel, James Altgens, who was standing next to the Limousine on Elm Street at the time of the head shot, claims that he heard Kellerman radio "We've been hit, get us to the nearest hospital" [Trask p. 315].
Thus, the alignment of the channels placing the time of the shooting immediately before Curry ordered his officers to go to the hospital is in accord with Kellerman's contemporaneous account of events. Nonetheless, it is also true that the timeline is not completely reliable. If it were true, as the NRC panel implied, that one can use crosstalk to synchronize events on the two channels, then one should be able to use any instance of crosstalk. but, it can be seen that whichever crosstalk one chooses, the others will not align. Several reasons have been offered to explain why the events on the two channels are out of synch.
Firstly, the original recordings were made on machines which utilized a stylus which etched an acoustic groove into a soft polyvinyl surface. The recording instruments were useworn and had developed idiosynchracies. Jim Bowles, head of police communications unit at the time, writes that the needles would sometimes not "groove" properly, that parts of messages would not be recorded, or a "ghost" signal would be recorded. He also states that it was a common experience to observe noticable changes in speeds between units [Bowles 1979].
Secondly, the original recordings had become scratched and worn from multiple playbacks during the transcription process that was applied during the Warren Commission's investigation. As a result, the tendency for the stylus head to skip was exacerbated.
Thirdly, both recorders had a sound-actuation feature which was designed to save space on the recordings by pausing whenever there were periods of dead-air. To the extent that this happened during the critical sequence of events there would be disagreement between tape time and actual time.
Fourthly, the electronic recordings which have entered into evidence involved the use of separate playback and/or recording instruments, sometimes both, which inevitably results in a time warp because playback speed and original recording speed are unlikely to match precisely.
The NRC panel undertook a study of the recordings for the purpose of identifying the discrepancies caused by these problems and to eliminate them to the extent possible. The timeline which you see here in Fig. 14 resulted from that study and are the time intervals presented in the NRC report at their table C-1. The reason that misalignments still remain is largely due to their use of the Bowles tapes. Bowles recorder ran out of tape half way through the critical sequence of broadcasts. Skips and repeats are numerous. It is suspected that the recorder stopped at times during the sequence and the duration of these silences cannot be measured directly. There is also evidence that either the audograph machine or Bowles tape recorder was varying in speed. The NRC panel was unable to resolve this issue completely. During the deliberations of the NRC panel, its members met with scientists from the HSCA investigation and attempted to resolve the differences. Each favored a different timeline and, for whatever reason, they failed to reach a consensus.
But there have been new developments on that front. In the last few months a new investigation of the channel 2 timeline has been undertaken by an expert named Michael O'Dell. O'Dell has graciously given me permission to show you this new channel 2 timeline (Figure 15). O'Dell acquired a copy of the channel 2 recording that was originally made by the FBI for the NRC panel directly from the original audograph disc. This recording was mentioned by the NRC panel but the timeline from this recording was not relied on because of a warp introduced by using a standard turntable (which plays at uniform revolution speed) instead of an audograph disc recorder (which plays at uniform track speed). The advantage of this recording is that it eliminates the skips and repeats which occur in playback with an audograph machine. What O'Dell has accomplished in his studies was to find a way to correct for the warp in speed caused by the difference in turntables.
The reasons for believing that this new timeline is a closer approximation of reality, or at least, has fewer artifacts, include, 1) it actually agrees closely with the same correction that the NRC panel used, but ultimately decided not to rely on, and 2) it agrees closely with the timeline preferred by BBN, arrived at using a completely different method. Over the six minute period of interest they agree within four seconds.
Now, as to the significance of this new timeline. The NRC panel and its defenders argue that a simple explanation for the discontinuities in the timeline, which we can see by comparing the crosstalk events, is the action of the sound activation feature which would cause the recorder on channel 2 to stop whenever there was dead air. The problem with that hypothesis, as I noted in my article, was that the dispatcher time notations are in close agreement to the actual elapsed time. As one can see in this graphic, the 12:32 time notation occurs exactly two minutes after the announcement of 12:30 and there is similar agreement with some of the others. This time notation at 12:36, is almost exactly six minutes after the 12:30 notation. If one assumes that the time discontinuity is due to a stoppage of the recorder and puts back a full missing minute between HOLD and YOU on channel 2, it throws the time notations unreasonably out of whack. I therefore argued that a stoppage of the recorder for a full minute in this sequence was implausible. An alternative explanation was that the stylus head had skipped during the recording process and that no significant amount of time had been added or lost.
O'Dell's new timeline however, by eliminating most if not all of the speed warps, skips and repeats, changes the juxtaposition of these events. As you can now see, if one uses the Bellah broadcast YOU to synchronize events, the shots no longer align with Curry's broadcast. Of course, because we should be free to use any crosstalk to synchronize the channels, if one uses the Henslee broadcast - "Attention all units...", which was actually a deliberate simulcast, not an accidental crosstalk, we re-arrive at synchroneity between the putative shots and the time of the assassination.
But importantly, O'Dell's new timeline reduces the time discrepancy between the two Decker broadcasts from one minute to only about 35 seconds. This reduction in the time discrepancy makes the hypothesis of the recorder stopping much more plausible. To put it in lay terms, my objection to the NRC's hypothesis is largely blown away.
But that doesn't mean that the hypothesis is correct, only that the hypothesis is now plausible. It is still not strong enough to refute the acoustic evidence. First of all, there is no direct evidence that the recorder stopped. Secondly, the jumping stylus theory is still in better agreement with the time notations than with the recorder stoppage theory.
Note, for example, that there is about a 20 sec offset between the Bellah and Henslee broadcasts on the two channels. One can fairly assume that this offset is due to missing time, perhaps due to a pause in the recorder. We can correct for the discrepancy by adding 20 sec to the timeline at a point just before the Henslee broadcast on channel 2. By doing so we achieve alignment between all of the crosstalks, except the Double Decker. Without the proposed correction, the mathematical agreement between the dispatcher time notations and timeline is 0.902. This is called a regression analysis, which to those of you who still play the lottery won't mean very much (on the reasoning that if you were good at math you wouldn't play the lottery). For others this value is called the slope and is a measure of the linear agreement between two variables. Once we apply the 20 sec correction, the mathematical agreement between the time notations and the timeline increases to 0.944 (see table 2).
The value of the slope will be one if there is a perfect agreement. This second value, called the intercept, will be zero if there is a perfect agreement. I have also shown a third value, "r" the regression coefficient, because statisticians would look for it, but the value doesn't change as you can see. With our proposed correction the slope moves closer to one and the intercept moves closer to zero. This gives us confidence that our proposed correction is reasonable. Similarly, you might have noticed that the 12:31 time notation on ch-2 was offline. This
Table 2.- Regression Analysis of Time Notations: and test of hypothesis that recorder stopped between HOLD and YOU.
Time Y X X X
Notation (sec) (sec) Corrected Hypothetical
12:30 0 0 0 0
12:31 60 95.8 95.8 95.8
12:32 120 121.2 121.2 156.2
12:34 240 212.8 212.8 247.8
12:35a 300 268.9 268.9 303.9
12:35b 300 300.3 300.3 335.3
12:36a 360 329.9 349.9 384.9
12:36b 360 358.8 378.8 413.8
Slope .902 .944 1.04
Intercept 14.8 10.7 16.0
r .99 .99 .99
w/o Slope .947 .991 1.07
12:31 Intercept 0.2 -4.8 6.6
r .99 .99 .99
might well have been due to the fact that the dispatcher had to wait for Sheriff Decker to stop talking on channel two before he could make his own broadcast. If we recalculate the agreement between the timeline and the other notations without the 12:31 notation, the slope again moves closer to one and the intercept moves closer to zero. Therefore, let us make both corrections. Though the intercept misses the mark a little, the slope becomes nearly perfect at 0.99.
One can apply the same reasoning to the hypothesis that the recorder stopped between the Decker and Bellah broadcasts. But when one adds the missing 35 seconds, the opposite happens. Both the slope and the intercept move away from agreement with the dispatcher's time notations. This evidence suggests that there is no time missing between the Decker and Bellah broadcasts, or at least, not as much as 35 sec.
Now we all remember what Mark Twain said about lies, damned lies and statistics. The regression analysis above does not prove one hypothesis over the other. Numbers only force us to be logical, not factual. There is no reason to believe that the dispatcher's time notations (other than the station identification at 12:30) were chronometrically exact. Moreover, a modern study, such as that applied to ch-2 by O'Dell has not yet been applied to ch-1. The point is that the uncertainties inherent to these timelines preclude them from being definitive proof that the putative gunshot sounds are or are not precisely synchronous with the time of the assassination, even if the regression analysis were to go the other way.
Our bottom line with regard to the timeline evidence is much like the bottom line with the microphone trajectory evidence. The evidence is not sufficiently definitive to say that the putative shots were or were not exactly synchronous with the assassination. One can fairly say that there is evidence that they might not be. But one can also say that they are certainly close - within the same minute of time.
ZAPRUDER FILM EVENTS
Earlier I endorsed the concept that all of the crime scene evidence should be considered in an assessment of the validity of a shot from the Grassy knoll. Abraham Zapruder's home movie is the single most important piece of evidence in the Kennedy murder. Of the many films of the assassination it is the most comprehensive. The 26 sec film has been used by all official investigations, including the Warren Commission and the House Select Committee on Assassinations as the standard chronometer of events. Although bullet impacts are gruesomely depicted in the film, the Warren Commission was unable to arrive at an explanation for the sequence and spacing of the gunshots coherent with the presumption of a single assassin. Thus, the official version posits that the apparent wounding of Governor Connally was a delayed reaction; that, against all medical expectations, a victim shot through the neck would raise his arms; that the assassin chose to shoot at, and managed to strike, a target he couldn't see; and it insists that a person shot from behind would be somehow thrust backwards. Then, just to top it off, a spent bullet devoid of any connection to any of the wounds, was declared to be responsible for nearly all of them!
Noted historian Barbara W. Tuchman once wrote an essay on "Practicing History." She wrote,
"It is wiser, I believe, to arrive at a theory by way of the evidence rather than the other way around."
Instead of forcing the evidence to fitting our presumptions, let us take that admonition to heart and see if there is cohesion between the acoustic evidence and the filmed evidence.
Events depicted in Zapruder's Film
A forensic study of the Zapruder film was conducted by the HSCA Photographic Evidence Panel. The film shows the passage of the President's limousine from the east end of Elm Street until it disappeared under the railroad underpass at the west end of Dealey Plaza. It is known that the shooting occurred during this sequence. A major impediment to the interpretation of the Zapruder film is that an intervening freeway sign blocks the view of the President for a critical second from frames 207 to 224. With that proviso, the panel found four episodes in the film in which the passengers of the President's limousine appeared to be reacting to a severe external stimulus.
A) Beginning at frame 165 Governor John Connally, sitting directly in front of the President, makes a rapid head movement 90 deg to his left, then turns completely around in the opposite direction to glance back over his right shoulder. In his testimony to the Warren Commission the Governor stated that he turned to look back in response to hearing what he believed was a gunshot [WCR:112].
B) In the sequence of frames 194 to 207 (at which point he disappears behind the sign) President Kennedy suddenly froze his waving hand and abruptly raised his right elbow which had been resting on the car windowsill. He then shook his head from right to left. During the same sequence, a young girl who had been running alongside the limousine, stopped abruptly and turned to look in the general direction of the Book Depository behind the limousine. Also during this sequence, Mrs. Kennedy, who was waving at the young girl, turned to look in the direction of the President (see Olson & Turner 1971).
C) Between frames 224 and 240 Governor Connally's posture stiffened, then contorted. His right shoulder dropped, his cheeks puff out and a look of anguish appeared on his face. He then collapsed into the arms of his wife seated next to him. During this same sequence, the President's arms, which were in a position folded in front of his body, appear to flap up at the elbows.
A 1967 photogrammetric study of the Zapruder film by the ITEK corporation, under contract to CBS News, revealed that following a stiffening of the Governor's posture at frame 224, his white Stetson hat, held in the right hand, flipped up and rapidly down at frames 227-229. In 1992 a study of an enhanced version of the film commissioned by the American Bar Association revealed that the right lapel of the Governor's jacket flapped outward at frame 224. Medical examination of the Governor immediately after the shooting revealed that he had been shot through the right side of his chest, the bullet exiting his rib cage and then striking his right wrist. The flap of the Governor's lapel, accompanied by his stiffened posture at frame 224, followed by clear evidence of anguish, indicates impact of the bullet at or about frame 224.
D) At frame 313 the President's head appears suddenly enshrouded by a halo of wound effluvia. Between frames 312-313 a forward jut of the President's head is measurable, but over the next 8 frames the President's head snapped backwards and he toppled over to his left. The visible wounding establishes the instant of impact of the fatal shot at just before exposure of frame 313. The motorcycle patrolmen behind and to the left of the President were splattered with brains and bloody brain fluid.
Table 3.- Reactions to External Stimuli in Zapruder Film
EVENT INITIAL FRAME REACTION DEPICTED
A Z - 165 CONNALLY SWIVELS HEAD - TURNS AROUND
B Z - 194 KENNEDY FLINCHES - ARMS CLUTCH
C Z - 224 CONNALLY LAPEL FLAPS - BODY STIFFENS
D Z - 313 KENNEDY SHOT - HEAD GOES REARWARD
Table 3 lists the episodes which the photogrammetric experts referred to as "visible reactions to severe external stimuli." Not listed in this table is another example of such a reaction. It is embodied by a 32 mm photograph of the President's limousine taken by a private citizen standing on the south side of Elm Street opposite Zapruder. Phillip Willis' photo (Fig. 17) is accorded some importance because both the President's limousine and the Grassy Knoll are simultaneously visible. The forensic value of the Willis photo is somewhat diminished because it is poorly focused. On the other hand, Willis explained in testimony that the photograph was blurry because he had involuntarily depressed the camera's shutter in response to being startled by the sound of gunfire [7 WCH 493]. Thus, the true significance of Willis' photograph is that it provides indirect evidence for the instant of one of the gunshots. Because Willis appears in Zapruder's film, and because Zapruder appears in Willis' photo, it is possible to accurately correlate the Willis photo to frame 202 of the Zapruder film [Olson & Turner 1971]. More importantly, Willis' reaction, and resultant blurred photo, suggested a novel method for analyzing the Zapruder film.
The rationale of a blur analysis is that the sound of gunfire should induce an involuntary startle reflex in the cameraman. The angular momentum imparted to the camera body by the resulting jiggle should be manifest as a blurring of the image in the film. Thus, a blur analysis provides a method for establishing the instants of gunfire. Moreover, such an analysis provides evidence on the proximity of the shooter because, regardless of when the bullet impacts the target, the startle reflex will not be induced until the sound reaches the listener.
There are four published blur analyses of the Zapruder film, all of which are in basic agreement as to the determination of the primary blur episodes. The concordance among the separate studies is offered as evidence that they were competently and reliably accomplished. However, there was only a limited attempt to correlate the identified blur episodes with the visual evidence of bullet impacts seen in the same film. There was even less effort to reconcile the instants of the blur episodes with bullet flight time, the speed of sound in air, or startle reaction time.
Camera and Film Specifics
Zapruder was using a new 8 mm, Bell & Howell, Model 414 PD, electric-eye, motion picture camera with a Zoomatic lens [Trask 1994]. Driven by a hand wound spring, the camera was fully wound, the lens was set to full zoom, and the optional speed control was set to expose 18 frames per second. The FBI laboratory determined that Zapruder's camera was running slightly faster at an average of 18.3 frames per second [WCR p. 97].
The Startle Reflex
The startle response is an involuntary, reflexive, muscular reaction mediated by the brain stem [Landis & Hunt 1939]. The audiogenic reflex is most reliably induced by a sudden, loud, percussive noise, and consists of a sequence of muscle contractions whose order is determined by the distance of the muscles from the brain stem, and the velocity of nerve transmission [Lee et al. 1996]. Electromyographic studies [Davis 1984] show that the first muscles to contract are the facial and jaw muscles beginning at 14 msec post-stimulus, inducing a characteristic grimace with the eyes squint shut and the teeth bared (Fig. 18.) At 25 msec the cervical muscles contract followed by the trapezius muscles at 40 msec. These contractions cause the head to tuck into the shoulders. Contraction of the muscles of the arms and shoulders starts the arms towards a position folded in front of the body. Finally, contraction of the leg muscles, at 120 msec post-stimulus, causes the knees to buckle. The intensity of the response will vary among subjects even though the reaction is involuntary. In medical applications the startle reflex is induced to assess neurological deficit in trauma victims and newborns, where it is referred to as the "Moro" reflex [Lang et al. 1990].
For the situation under consideration, with a motion picture camera held by hand at a level with the operator's face, the movement of the neck and shoulders at 25-40 msec would be expected to cause the initial detectable blur. Because Zapruder's camera was exposing film at the average rate of 18.3 frames per sec, or 55 msec per frame cycle, the sequence of involuntary muscular contractions, followed by voluntary recovery movements, result not in a single blurred frame, but a chain of blurred frames; a blur episode. As with other physiological reactions to stimuli, the magnitude of the reaction is often a function of the strength of the stimulus, and, there is often an attenuation of the reaction with habituation [Burnham 1939]. Which is to say, that if the stimuli are not discrete, but in a closely spaced sequence of stimuli, then only the initial stimulus might be expected to induce a strong reaction. In the context of the Kennedy assassination, if there were shots only a split second apart, as some critics have suggested, the secondary shots would not be reliably detected by the blur analysis. Conversely, a sequence of frames without blur would be evidence for the absence of gunfire.
The Acoustic Environment
Ambient noise levels from the crowd at the time of the President's motorcade were estimated to reach 90 deciBels [5 HSCA 671]. According to both official accounts of the assassination, the Warren Commission (1964) and the House Select Committee on Assassinations (1979), the shots which struck President Kennedy originated from a sixth floor window of the Book Depository in the northeast corner of the plaza. Zapruder's location was 270 ft linear distance from this window [6 HSCA 27]. The alleged murder weapon, a 6.5 mm Mannlicher-Carcano Italian carbine, produces a muzzle-blast with a sound pressure level of 137 deciBels at a distance of 30 ft from the muzzle [8 HSCA 56]. At Zapruder's location the sound pressure level is estimated to have been around 118 deciBels [8 HSCA 58] (as perceived by a human listener, loudness doubles with each increment of 10 deciBels).
The alleged murder weapon could not be rapid fired. Tests by the FBI laboratory established that the minimum cycle time was 2.3 sec [3 WCH 407]. Allowing additional time to reacquire the target means that separate shots from this weapon would have been in discrete intervals of several seconds, and thus, each would be expected to induce separate, non-overlapping startle reactions in Zapruder. Empirical evidence that the shots would have induced a startle reflex was provided by Edgerton, Germeshausen & Greer, a consultant firm under contract with CBS News in an experiment conducted in 1967. Two naive subjects, each with a hand-held movie camera, were instructed to pan on a passing automobile, as was Zapruder. At a distance of 270 ft from the cameramen a Mannlicher-Carcano was fired three times at three second intervals. Films of the experiment show both subjects exhibiting the startle response, a marked flinch, in response to each individual shot [see Richter 1991].
Determination of Primary Blur Episodes
The first blur analysis of the Zapruder film was conducted by physicist Luis Alvarez and published as a transcript of an interview which he gave CBS News in 1967 [White 1968]. Alvarez later published a revised version of this study in 1976. Alvarez, who had developed camera stabilizers for Bell & Howell, recognized that most of the blur or poor focus in Zapruder's film would be attributable to panning error. Alvarez found a method to separate the blur due to ordinary panning error from the blur induced by a startle reaction.
The President's limousine was studded with chrome fixtures which reflected sunlight. When any individual frame is in good focus the reflection of the sun appears as a round, white, spot. Anytime the camera was panned too slow or too fast relative to the motion of the automobile, the spots become elongated. Measuring the length of these highlights provided a direct measurement of panning error. The critical criteria for identifying a jiggle is not the length of the spots, but rather, the difference in length of the spots between adjacent frames. Because the camera was exposing frames at the speed of 18.3 frames per second, the difference in the length of the spots between any two adjacent frames was bound to be small regardless of their actual length if the blur was due to ordinary panning error. But a sudden, rapid jiggle of the camera, of the sort associated with a startle reaction, should be detectable as a large difference in spot length between adjacent frames. These two critical frames from the Zapruder film show the highlights that we are measuring (Fig. 20). In frame 312 the highlights are round spots. At frame 313 they are greatly elongated.
Alvarez measured the difference in the length of the highlights in all frames published by the Warren Commission and identified the three largest jiggles as beginning at frames 194, 227 and 313. Because the latter corresponds exactly to the one frame in which there was unequivocal evidence of bullet impact, a degree of confidence attached to the method used in the analysis.
"At frame 227, the highlights on the windshield of the car are all drawn out into rather pronounced streaks. And you can see that in the frame ahead the highlights are individual dots. And again in the frame beyond them are individual dots. So something rather violent happened to the line of direction of Mr. Zapruder's camera in frame 227. It swung violently."
[White p. 226]
To confirm the validity of the determined blur episodes, CBS News contracted with Dr. Charles Wyckoff for an independent replication of Alvarez's result. Wyckoff concurred with the initiation of blur episodes at frames 227 and 313 but reported that the first sequence appeared to initiate slightly sooner, at frame 190 [White 1968].
In his subsequent revised analysis, Alvarez concurred that the first episode was initiated earlier, moving it to frame 182. Moreover, he identified two other large blurs at frames 290 and 330. However, the revised analysis contains a serious error. In attempting to reconcile the blur episodes with the evidence of bullet impacts, Alvarez introduced a six-frame correction factor for a supposed delay in startle reaction time. But, this hypothesized six frame delay, about one-third of a second, was based on voluntary muscle reaction time. The startle reaction is an involuntary reflex with an onset in 25-40 msec, less than one frame cycle.
In 1978 the HSCA Photographic Evidence Panel undertook its own blur analysis of the Zapruder film. The panel's analysts, William K. Hartmann and Frank Scott, measured the elongation of the highlights on the limousine, as did Alvarez, but not the change in elongation. This approach was thus more sensitive to panning error, but less sensitive to angular momentum, the method used by Alvarez. In addition, they measured the vertical and horizontal displacement of non-mobile background features from one frame to the next. Using these different approaches, they arrived at essentially the same determinations as those of Alvarez and Wyckoff. The panel identified the onset of blur episodes at frames 191, 227, 313 and 331. Moreover, whereas Alvarez and Wyckoff were restricted to the study of frames published by the Warren Commission, the HSCA panel had a copy of Zapruder's entire film. Hartmann and Scott were able to identify an additional large blur episode beginning at frame 158. In a modern review of the blur evidence, Michael Stroscio concurred with the identifications of the blur episodes but determined that the first episode initiated somewhat earlier, at Z-152. Table 4 provides a compilation of the results of the separate analyses.
Aside from the basic agreement in the identification of the blur episodes among the different approaches and different analysts, it should be noted that the identified blur episodes correspond to events that are visualized in the Zapruder film. The fatal head shot is coincident with blur episode (A). Governor Connally's swivel occurred immediately after blur episode (E). President Kennedy's flinch occurred within a split second of blur episode (C). The wounding of the Governor is attended by blur episode (D). There is no overt "reaction to external stimuli" in the film associated with the blur at Z-330, but by then the victims had been knocked down and the other passengers were already reacting to the assassination.
Because there is no overt evidence of bullet impact associated with the postural changes by the Governor at frame 165 and by the President at frame 194, there was doubt that their reactions were actually responses to gunfire. The presence of attendant blur episodes is of interest in the context of missed shots, because it suggests that the President's and Governor's visible reactions were at least coincident with a stimulus which caused Zapruder to jiggle his camera. Of even greater significance is the blur episode attendant to the visible wounding of the Governor, which is relevant to the issue of whether or not the Governor's reaction was delayed.
Table 4.- Blur episodes in the Zapruder film identified by five different investigators using three different methods explained in the text. Frame numbers indicate the onset of each of the five largest blurs, A-E in order of magnitude.1
Onset of Blur Episodes
A B C D E
Angular Acceleration 313 330 182 227 290 1
(Alvarez 1967, 1976)
Angular Acceleration 313 - 190 227 -
Angular Acceleration 313 330 180 227 152
Panning Error 313 331 191 227 158 1
Background Displacement 313 331 193 226 158
1 The values obtained by Hartmann and Scott (1979) and by Alvarez (1976) appear at 8 HSCA 30. The frame numbers attributed to Alvarez (1976) in that table differ somewhat from the frame numbers stated in Alvarez's text because the latter included an erroneous correction factor. For their table, Hartmann and Scott read the values directly from Alvarez's figure.
Startle Reaction and Bullet Flight Time
Whatever stimulus might be associated with blur episodes C, B, and E, episodes A and D are clearly associated with bullet impacts. The application of simple physical principles to this evidence reveals critically important information about the origin of the gunfire. The jiggle of the camera indicated by the blurring of the image occurs when the cameraman is startled by the sound of the gunshot. This involuntary reflex will affect the camera body approximately 25-40 msec after the sound arrives at the cameraman's ear. The speed of sound through air is a function of the air temperature. As it happens, there was a large digital display of time and temperature in Dealey Plaza which was captured in contemporary photographs. At 12:40 PM this sign displayed an ambient temperature of 65F [5 HSCA 643]. At this temperature the speed of sound in air is 1123 ft/sec.
The flap of the lapel on Governor Connally's jacket seen in frame 224, tends to establish the instant of bullet impact given that the Governor was shot through the chest at a point near the lapel and over the next second (frames 224-240) he stiffened, contorted, and collapsed in the arms of his wife. If the bullet originated at the sixth floor window of the Book Depository, the bullet would have traveled 190 ft to reach the limousine [WCR p. 103]. The U.S. Army Infantry Weapons testing branch determined that the muzzle velocity of the alleged murder weapon was 2165 ft/sec and, due to the slowing from air resistance, it would have impacted with a velocity of around 1907 ft/sec [5 HSCA 75-77]. Therefore, average velocity over this distance would have been 2036 ft/sec. At this velocity the bullet flight time from origin to impact would have been 93 msec. Thus, trigger time was at impact time minus 93 msec. Abraham Zapruder was 270 ft from the sixth floor window of the Book Depository [6 HSCA 27]. The time for the sound of the muzzle blast to reach Zapruder would have been 239 msec after trigger time, or 145 msec after impact time. With a frame cycle of 55 msec, the sound of the gunshot would have reached Zapruder a little less than 3 frames after impact. Thus, with an instant of impact in the interval between frames 223 and 224, the sound would have reached Zapruder's ear between frames 226 and 227. Allowing 25-40 msec for reaction time, Zapruder should be startled and jiggle of the camera would be detectable at frame 227. That is exactly where the analysts found the blur episode to begin.
This reconciliation tends to corroborate that the flap of the lapel on the Governor's jacket does establish the instant of bullet impact and that the bullet could have originated on the sixth floor of the Book Depository. Although this conclusion contradicts assertions that the Governor's reaction might have been delayed, the result is especially impressive in that Alvarez and Wyckoff identified the blur at frame 227 in 1967, confirmed by the HSCA panel in 1978. The flap of the Governor's lapel was not reported until 1992. And there is additional evidence. This blurry photograph of the President's limousine (Fig. 21) was taken by Charles Bronson. Bronson asserts that the photograph was taken involuntarily because he was startled by the sound of a gunshot [Trask p. 234]. Because the rear tire of the limousine is in line with a small tree east of the Pergola, we can synchronize this photograph to about Z-229. The slightly later reaction is due to Bronson being about 100 ft farther away from the Sniper's Nest than was Zapruder.
One can apply the same analysis to the unequivocal evidence of impact at frame 313 to reach a startling conclusion. The blur which is coincident with this frame, the largest blur episode in the Zapruder film, occurs much too soon to be caused by a gunshot from the Book Depository. Because nothing extraordinary is visible in frame 312, all analysts have concluded that the impact must have occurred during the 27 msec interval between the exposures of frames 312 and 313 when the shutter occluded the lens. But, inasmuch as the effects of bullet impact are so vivid in the latter frame, it is possible to be more precise in establishing the instant of impact. The frame shows fragments of bone egressing the President's skull at ballistic velocities. The ITEK Corporation analysts calculated the velocity of the fragments at approximately 100 ft/sec. The largest fragment appears as a 1.3 m long white streak creating a string of pearls effect. The effect results from the flat bone flipping end over end as it spins away from the cranium during the 27 msec exposure time of the frame. Importantly, the white streak begins about one ft away from the head, indicating that the exposure of the frame began a few msec after the bone separated from the skull. Studies of bullet impacts with fluid filled vessels using high speed photography show that the pressure wave which ruptures the skull occurs about 5-10 msec after passage of the bullet [Lindenberg 1971, Di Miao 1993]. Thus, impact time might have been as early as 15 msec prior to the exposure of frame 313, near the midpoint of the shutter closure between frames.
The initiation of the exposure of frame 313 can be used as an anchor point time, to, with earliest bullet impact estimated at to-15 msec. President Kennedy was 265 ft from the sixth floor window at the time of the fatal shot [6 HSCA 27]. The Army's weapons experts measured the velocity of the bullet from the alleged murder weapon at 90 yd to be 1600 ft/sec [1 HSCA 413-414]. Thus, the average velocity would have been 1880 ft/sec and the bullet flight time to cover 265 ft = 141 msec. Therefore, trigger time, assuming an origin in the Book Depository, would calculate to to-156 msec. As before, the sound would have taken 240 msec to reach Zapruder, arriving at time to+84 msec. Given the minimum of 25 msec for latency in induction of the startle reaction, the earliest that the camera body could have jiggled would be at 109 msec after the initiation of frame 313, producing a blur at frame 315. The relevant times are shown in a schematic (Fig. 22). It is perplexing then, that the report of the HSCA Photographic Evidence Panel contains the unsupported and unqualified statement,
"...it is possible to determine that the sound from that shot would have reached Zapruder at frame 313-314..."
On the contrary, it is not possible for the sound to have reached Zapruder's position prior to frame 313 or 314 unless one posits some sort of cartridge anomaly. Moreover, because of the latency in reaction time, the sound has to arrive well before the exposure of frame 313 in order to account for the blur in that frame. In his published analysis, Alvarez acknowledged that it was not possible for the sound of the gunshot to arrive before the end of frame 313. Alvarez offered a different solution. Alvarez conjectured that the sound pressure from the shock wave of the passing bullet could have moved the camera body! Indeed, the sound pressure of the shock wave would have been significant; around 110 deciBels. But, as was the case with the HSCA panel, Alvarez failed to provide calculations in support of his supposition that the shock wave could have arrived in time to account for the jiggle.
The shock wave emanates from the nose of the bullet as it rips through the air. The closest that the bullet ever came to Zapruder, if it did come from the Book Depository, was the instant before it struck the President. Zapruder was 73 ft from the President at the time of the fatal shot [6 HSCA 39]. The shock wave emanating from the bullet would have taken 65 msec to travel the distance from this point in its path to Zapruder. From earliest impact time at to-15 msec the shock wave would impinge on the camera body at 50 msec after the beginning of the exposure of frame 313, i.e., at about the beginning of the exposure of frame 314, much too late to account for the blur in frame 313.
Alternatively, the backward head snap could be explained by the momentum imparted by a bullet with an origin from the front of the President. Many witnesses, one of them Abraham Zapruder, testified to the Warren Commission that they thought the shot originated from the area known as the Grassy Knoll, a position behind and to the right of Zapruder. Zapruder explained [7 WCH 572],
"I...thought it came from back of me. Of course you can't tell when something is in line...I have no way of determining what direction the bullet was going...there was too much reverberation. There was an echo which gave me a sound all over."
The corner of the fence on the Grassy Knoll was only 53 ft behind and to the right of Zapruder's position. Some individuals reported seeing a man with a .30-30 rifle running from the scene of the assassination [WCE 1974, p. 24]. A .30-30 factory load cartridge (170 grain bullet) has a muzzle velocity of 2200 ft/sec. Ballistic tables show the velocity of this bullet at 100 ft has dropped to 1895 ft/sec [Shooters Bible No. 83]. The President's position was 93 ft from the corner of the fence at the time of the fatal shot [8 HSCA 98]. Average velocity over this distance would have been 2050 ft/sec, giving a bullet flight time of 48 msec. Thus, trigger time would have been at to-62 msec. The sound of this shot would have reached Zapruder in 53/1123 = 47 msec, i.e. 15 msec before the initiation of the exposure of frame 313. Allowing for 25 msec latency, the startle reaction would have jiggled the camera body during the exposure of frame 313.
The startle reaction is an involuntary neuromuscular reflex. The experiments conducted for CBS leaves little doubt that the gunfire that killed President Kennedy would have startled Zapruder. If the blurriness of the picture in frame 313 of the Zapruder film is due to a startle reaction to the fatal gunshot, as all analysts have concluded, the shot had to have originated from a position very much closer to Zapruder than the sixth floor of the Book Depository, in fact, within less than about 100 ft, and only then if one assumes a weapon with the lowest velocity rifle ammunition commercially available. One would not want to posit conspiracy on a hiccough, and thus the blur at frame 313 should not be considered proof that a gunshot issued from the Grassy Knoll. However, the evidence from the blur analysis is consistent with an origin on the Grassy Knoll. Contrary to the unsupported assertions of previous analysts, the evidence is not consistent with an origin on the sixth floor of the Texas School Book Depository; the location identified in the official reports.
CONSPIRACY OR COINCIDENCE?
The close agreement between the time sequence of impacts seen in the Zapruder film and the time sequence of gunshots on the police audio tape provides a basis for a coherent reconstruction of the crime. Table 5 provides a synchronization of the acoustic and filmed evidence to show the cohesiveness among the three lines of evidence. Particularly compelling is the 4.8 sec interval between the third shot on the dictabelt and the Grassy Knoll shot compared to the same 4.8 sec interval between the strike on the Governor at frame 224 and the head shot inflicted on the President at Z-313. The blur analysis corroborates the interpretation of the lapel flap and stiffening of the Governor's body for the moment of impact. Thus, bullet flight time and the speed of sound support that the third shot was fired from the Texas School Book Depository, but the same evidence indicates that the fourth shot was fired from the Grassy Knoll and was the shot that killed the President as seen in the Zapruder film. For students of the assassination the evidence is a double-edged sword. While the integration of the acoustic evidence with the filmed evidence supports allegations of conspiracy, it also supports the contention that John Kennedy and John Connally were struck by a single bullet.
Table 5.- Synchronization of Audio and Video Evidence
ACOUSTIC Z-FRAME BLUR Z-FRAME FILM EVENT
EVENT EQUIVALENT START ACTION DEPICTED
Noise Z - 147 Z - 152 Z - 165 Connally head swivel
TSBD Shot Z - 175 Z - 180 Z - 194 Kennedy flinches
Rogue Shot Z - 204 Z - 202 Z - 202 Willis shutters
TSBD Shot Z - 224 Z - 227 Z - 224 Lapel Flap
Knoll Shot Z - 312 Z - 313 Z - 313 Head Shot
TSBD Shot Z - 326 Z - 330 none none
For a generation, there has been an abject refusal to accept obvious evidence for a gunshot from the Grassy Knoll, most conspicuously, the rearward snap of the President's head following the impact of the fatal bullet. But conspiracy buffs have been equally tenacious in their refusal to accept the single bullet theory. Both religions cling dogmatically to these tenets of belief.
The single bullet theory has been the single largest obstacle to obtaining a coherent reconstruction of the crime. One of the underlying constraints is a failure to disentwine the single bullet theory from its corollary, the magic bullet theory. Once those bonds are disconnected, it becomes clear that most if not all of the the flaws in the single bullet theory are attached to Commission Exhibit 399. The neutron activation analysis of the bullet fragments, the soft x-ray analysis of the bullet holes in the clothing, the deposition of fibers in the Governor's wrist wound, the contradiction between the deformation velocity of this type of bullet and the practically unscathed condition of this bullet, and the failure to establish any connection between this bullet and either victim, all mitigate against CE-399 having anything to do with anyone's wounds.
But reconsider the problem in the light of the audio-video evidence with CE-399 removed from the picture. If President Kennedy was killed by a shot from the Grassy Knoll, CE-567 cannot have come from the head wound as the Warren Commission supposed. But, Commission exhibit 567, the broken bloody bullet found in the front seat of the limousine, gives a good fit to the single bullet theory. I think most researchers on the conspiracy side accept that CE-567 probably caused Governor Connally's wounds. But they balk at the idea that it might have passed through Kennedy first.
The acoustic evidence indicates but one shot from the front. This synchronizes to the head shot. This requires that the President's upper torso/neck wound be received from the rear. Beginning at Zapruder frame 194 the President assumed a posture that can best be described as a flinch which included bringing his arms in front of his body and shaking his head back and forth. According to Secret Service agent Roy Kellerman, he also spat out the words, "My God, I'm hit." Because the Warren Commission claimed in contradiction to all medical expectations that the President was clutching at his throat wound, I feel compelled to point out that a person who has had his trachea perforated by a bullet is unlikely to be capable of coherent speech, and a person who has had severe blunt trauma of the spinal cord at the level of the neck is not likely to be capable of deliberate arm movement. Studies of gun shot wounds involving the vertebrae are uniform in reporting flaccid paralysis of the muscles innervated downstream from the trauma (Cash 1977, Groat et al., 1945, Heiden et al, 1975, Ogilvy & Heros 1988, Vogel 1983, Raimond & Waterman-Taylor 1986, Yashon et al. 1970). Studies with animal subjects establish that the flaccid paralysis is induced instantaneously (Walker et al., 1977). What this means is that President Kennedy's visible reaction beginning at frame 194, about one sec after the shot detected at Z-175, could not have been a reaction to being shot through the neck. Therefore, the first shot must have been a miss.
On the other hand, the President's last words, "My God, I'm hit," coupled with his visible reaction, suggest that he was indeed hit - but, by shrapnel. Mrs. Virginia Baker, standing in front of the Book Depository reported seeing a bullet hit the street near the President [12 HSCA 20]. When the bullet splintered on impact with the roadbed it sent shards sailing toward the limousine. Secret Service Agent Warren Taylor was looking towards the President's car when the round disintegrated. He recounted the incident in his report.
"I heard a bang which sounded to me like a possible firecracker --the sound coming from my right rear. Out of the corner of my eye and off slightly to the right rear of the car, I noticed what now seems to me might have been a short piece of streamer flying in the air close to the ground, but due to the confusion of the moment, I thought that it was a firecracker going off."
[28 WCH 783-784]
Postal Inspector Harry Holmes testified that he saw the passengers flinch as debris flew up into the limousine [7 WCH 289-308]. Holmes was watching from the Post Office building through binoculars, but a closer witness saw the same thing. Mrs. Jack Franzen was standing at the Elm Street curbside with her husband and son as the limousine passed. The FBI reported her description of the incident.
"She advised shortly after the President's automobile passed on Elm Street near where she and her family were standing, she heard a noise which sounded to her as if someone had thrown a firecracker into the President's automobile. She advised at approximately the same time she noticed dust or small pieces of debris flying from the President's automobile."
The x-ray of the President's head taken at the autopsy revealed a metal fragment on the outside of the cranium located 10 cm dorsad of the occipital protuberance. The scalp wound in apposition to this piece of metal was described in the autopsy facing sheet [7 HSCA 253] as "ragged, slanting" with an arrow indicating an upward trajectory. Dr. Russell Fisher, the chairman of the forensic pathology panel appointed by Attorney General Ramsey Clark to review the autopsy materials concluded that the piece of metal was, "...most likely a richochet fragment" [interview in Menninger pp. 64-66].
I am not a forensic pathologist, but Dr. Fisher's expert diagnosis meshes well with the filmed evidence of the President's reaction, the accounts of the eyewitnesses, and explains the ragged nature of the scalp wound. Or, we may choose to rely on the HSCA Forensic Pathology panel's expertise on how this piece of metal came to be lodged on the outside of the President's skull. The Warren Commission's doctors elected not to report this piece of metal in their autopsy protocol. The forensic pathology panel met with the Chief Prosector, James Humes, and asked him about the fragment and scalp lesion. Transcripts of the panel's discussion elicited the following opinion from Dr. George Loquvam.
COE: "The reason we are so interested in this, Dr. Humes, is because other pathologists have interpreted the..."
LOQUVAM: "I don't think this belongs in the damn record."
HUMES: "Well, it probably doesn't."
LOQUVAM: "You guys are nuts. You guys are nuts writing this stuff. It doesn't belong in the damn record."
[7 HSCA 255].
One might be forgiven for suspecting that the good Doctor's reticence in discussing the origin of this fragment, on the record, might stem from the fact that if the "other pathologists" are correct, then the lesion in the scalp in the rear of the head would be explained, leaving no medical evidence for a head shot inflicted from the rear. No such discord affects the synchronization of the acoustical and filmed evidence.
Because the President could not have been shot through the back by the first shot, the next candidate for a wounding shot is the impulse identified at Z-frame 204. This shot seems to have caused Phil Willis to flinch, depressing his shutter button and exposing his famous photograph of the President's limousine. However, because this shot occurs so close following the first shot, and so soon before the next shot, it could not have come from Oswald's rifle, according to the U.S. Army Weapons Testing Branch. This is the rogue shot. I am unaware of any evidence that would support the hypothesis that a rogue bullet caused any wounds. But, there is evidence that the bullet which hit Governor Connally at Z-224 also hit President Kennedy. That evidence is the elongation of the entrance wound in the governor's back. A bullet hitting straight on would normally make a rounded perforation. The governor's wound was 0.5 cm wide and 1.5 cm long. The elongation can be explained by a bullet entering sideways from tumbling caused by an earlier impact. This argument may not be strong enough to be conclusive. But it is coherent and gives the best fit to the evidence, which is not the way that the Single Bullet theory is usually described.
In conclusion, the sequence of gunshots identified by the acoustical evidence meshes closely with the sequence of victim reactions, including impacts, seen in the Zapruder film. Moreover, the timing and origin of gunshots revealed by the acoustical evidence is cohesive with the indirect filmed evidence of audiogenically induced camera movements, by Zapruder, Willis and Bronson. The impulse patterns on the police radio tapes match the echo patterns of test shots fired in Dealey Plaza to a degree greater than would be expected by chance. The topological distribution of matching microphone positions among the array of test microphones falls in the order required by the working hypothesis that the sounds were recorded by a microphone traveling north on Houston Street and then westerly on Elm Street during the assassination. Analysis of the radio dispatcher's time notations reveals that the sounds were recorded within a minute of, if not exactly at, the moment that the President was assassinated. Newsreels show that a motorcycle was close to, if not exactly, at the positions predicted by the acoustical evidence, and its operator testified that he had a problem with a microphone that was prone to sticking open.
The author is most grateful to Gary Mack, Michael O'Dell, Tony Marsh and Jim Barger for their help in bringing this information together. Chris Mari Van Dyck assisted in preparation of the visuals. I especially want to thank Debra Conway and Ed Dorsch for making their venues available to me for this exposition.
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1. Oscillographs of Grassy Knoll shot
2. Microphone arrays.
3. Table 1.
4. Bond photo
5. Motorcycle trajectory
6. Hughes film frame 20---Note: Do to copyright usage agreement, unable to show on this website
7. Map of motorcade at Z-160
8. Map of motorcade in H-20
9. Map of Car-8 at Z-220 and H-20
10. Still from Couch film
11. Map of vehicles in Couch film
12. Altgens photo
13. Map showing Altgens field of view.
14. Timeline of police broadcasts
15. New timeline by O'Dell.
16. Table 2.
17. Willis photo
18. Moro reflex
19. Table 3
20. Zapruder frames 312-313
21. Bronson Photo
21. Results of Blur studies
22. Schematic of bullet flight time