HEAR
NO EVIL
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.
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
Back
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Kennedy Assassination for the Novice
