THE
ACOUSTICAL EVIDENCE IN THE KENNEDY ASSASSINATION
Presented
by
Dr.
Donald B. Thomas
November
17, 2001
Dallas,
Texas
(Copyright
2001 by Donald B. Thomas--reprinted here with author’s permission)
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.
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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
Back
to: The
Kennedy Assassination for the Novice