HEAR NO EVIL
THE ACOUSTICAL EVIDENCE IN THE KENNEDY ASSASSINATION
Presented by
Dr. Donald B. Thomas
November 17, 2001
Dallas, Texas
USA
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."
[Koenig
52(11):8]
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."
[Koenig
52(11):5]
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
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
[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
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
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
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
that I talked just now, a
flurry of
[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
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
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
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
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.
EPISODIC BLURS
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,
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
Onset
of Blur Episodes
A B C D E
Angular Acceleration
313
330
182
227 290
(Alvarez 1967, 1976)
Angular Acceleration
313 -
190 227
-
(Wyckoff 1968)
Angular Acceleration
313
330
180 227 152
(Stroscio 1996)
Panning Error
313
331
191 227 158
(Hartmann 1979)
Background Displacement 313 331 193 226 158
(Scott 1979)
1
The values obtained by Hartmann and Scott (1979) and by Alvarez
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
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
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
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
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
"I heard a bang which sounded to me like a possible firecracker --
[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.
[WCE-2090].
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.
Acknowledgements
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.
References
Alvarez.
L.W. (1976). A physicist examines the Kennedy assassination film. Am. J.
Physics 44: 813-827.
Bowles,
J.C. (1979). The Kennedy Assassination Tapes: a rebuttal to the acoustical evidence
theory. Reprinted in G. Savage (1993), JFK: First Day Evidence. The
Shoppe Press, Monroe, LA.
Burnham.
R.W. (1939). Repeated auditory stimulation of the startle response in the
guinea pig. J. Psychol. 7: 79-89.
Cash,
J. (1977). Neurology for Physiotherapists. Faber & Faber, London.
Davis,
M. (1984). The mammalian startle response. Pp. 287-345, In, Eaton, R.C.
[ed.] Neural Mechanisms of Startle Behavior. Plenum Press, NY.
Di
Maio, V.J.M. (1993). Gunshot Wounds: practical aspects of firearms,
ballistics, and forensic techniques. CRC Press, Boca Raton, FL.
Eccles,
J.C. (1974). Excitatory and inhibitory mechanisms in brain. Pp. 229-252,
in: Jasper, H.H., A.A. Ward & A. Pope [eds.]. Basic Mechanisms of
Epilepsies. Little, Brown & Co., Boston MA.
Groat,
R.A., W.A. Rambach & W.F. Windle. (1945). Concussion of the spinal cord.
Surg. Gynecol. & Obstet. 81: 63-74.
Heiden,
J.S., M.H. Weiss, A.W. Rosenburg, T. Kurze, & M.L. Apuzzo. (1975). Penetrating
gunshot wounds of the cervical spine in civilians. J. Neurosurg. 42:
575-579.
Hollien.
H. (1990). The Acoustics of Crime: the new science of forensic acoustics.
Plenum Press. New York, NY.
HSCA.
1979. U.S. Congress, House of Representatives. Investigation of the
Assassination of John F. Kennedy. Select Committee on Assassinations, 95th
Congress. House Report 95-1828. U.S. Government Printing Office. Washington
D.C. 1979. (Add. 8 vol. Hearings).
Klemm,
W.R. (1990). Historical and introductory perspectives on brainstem
Koenig,
B.E. (1983). Acoustic Gunshot Analysis: The Kennedy Assassination and Beyond.
FBI Law Enforcement Bull. 52 (11):1-9 [pt. 1]; (12):1-9 [pt. 2].
Landis
C. and W.A. Hunt. The Startle Pattern. Farrar & Rinehart, New York,
NY. 1939.
Lang,
P., M.M. Bradley and B.N. Cuthbert. (1990). Emotion, attention, and the
startle reflex. Psychol. Rev. 97: 377-395.
Lee,
Y., D.E. Lopez, E.G. Meloni and M. Davis. A primary acoustic startle
pathway: obligatory role of cochlear root neurons and the nucleus reticularis
pontis caudalis. J. Neurosci. 16 (1996): 3777-3789.
Lindenberg,
R. (1971). Trauma of Meninges and Brain. Chapter 133, in Minckler, J.
[ed.], Pathology of the Nervous System (2 vol.) McGraw-Hill, New York,
NY.
Menninger,
B. (1992). Mortal Error, the Shot that Killed JFK. St. Martins Press,
New York, NY.
NATIONAL
RESEARCH COUNCIL, Committee on Ballistic Acoustics. (1982). Reexamination of
Acoustic Evidence in the Kennedy Assassination. Science 218: 127-133.
NATIONAL
RESEARCH COUNCIL (1982). Report of the Committee on Ballistic Acoustics.
No. PB83-218461. U.S. Dept. Commerce, Natl. Tech. Info. Serv., Springfield, VA.
Ogilvy,
C.S. & R.C. Heros. (1988). Spinal cord compression. Chapter 22 in Ropper, A.H. & S.F. Kennedy [eds]: Neurological
and Neurosurgical Intensive Care. Aspen Publ. Inc. Rockville, MD.
Olson,
D. and R.F. Turner. (1971). Photographic evidence and the assassination of
President John F. Kennedy. J. Forensic Sci. 16: 399-419.
Raimond,
J. & J. Waterman-Taylor. (1986). Neurological Emergencies: effective
nursing care. Aspen Public. Rockville, MD.
Richter,
R. [Producer]. (1991) Who Killed John F. Kennedy. NOVA, PBS documentary
video.
SHOOTERS'S
BIBLE No. 83. (1992) W.S. Jarrett [ed.]. Stoeger Publ. South Hackensack, NJ.
1992.
Thomas,
D.B. (2001). Echo correlation analysis and the acoustic evidence in the
Kennedy assassination revisited. Science & Justice 41: 21-32.
Trask,
R.B. (1994). Pictures of the Pain: photography and the assassination of
President Kennedy. Yeoman Press, Danvers, MA.
Vogel,
H.B. (1983). Trauma of the head, spine and peripheral nerves.
Chapter
9, in: Earnest, M.P. [ed.]: Neurologic Emergencies. Churchill
Livingstone, New York, NY.
Walker,
J.G., R.R. Yates, J.J. O'Neill & D. Yashon. (1977). Canine spinal cord
energy state after experimental trauma. J. Neurochemistry 29: 929-932.
Warren
Commission Report. 1964. Report of the President's Commission on the
Assassination of President John F. Kennedy. U.S. Government Printing
Office, Washington D.C. 1964. (Add. 26 vol. Hearings).
White.
S. (1968) Should We Now Believe the Warren Report. Macmillan, New York,
NY. 1968.
[transcript
of CBS program 1967, see also, Richter 1991].
Yashon,
D., J.A. Jane & R.J. White. (1970). Prognosis and management of spinal cord and cauda equina bullet injuries in
sixty-five civilians. J. Neurosurg. 32: 163-170.
FIGURES
1. Oscillographs of Grassy Knoll shot
2. Microphone arrays.
3. Table 1.
4. Bond photo
5. Motorcycle trajectory
6. Hughes film frame 20
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
