Thompson's New Book Powerfully Confirms the HSCA Acoustical Evidence

[Michael T. Griffith]

The paragraphs below are segments from chapter 18 of the first edition of Dr. Thomas’s book Hear No Evil (2010). Chapter 18 deals with the identification of the patrol bike with the open mike. Dr. Thomas spends considerable time in that chapter dealing with Dale Myers’ research on the position of McClain’s bike. To get the full impact of Dr. Thomas’s arguments, you need to read the entire chapter, because, as mentioned, the paragraphs below are only some of the paragraphs in the chapter.

A film of the President's visit compiled by Dallas Cinema Associates
contains a segment showing the motorcade on Main Street approaching
Dealey Plaza. Patrolman McLain, identified by his license plate number 352,
appears in the film at a position just a little back from one of the convertible
press camera cars (tenth in the motorcade) and just ahead of a car with
dignitaries.5 Farther up Main Street one can easily discern the motorcycles
flanking the presidential limousine. Importantly, there are no other
motorcycles between McLain and the President on the left-hand side of the
motorcade as it approached Dealey Plaza.

In testimony to the Assassinations Committee in December, 1978, McLain
confirmed the identification of himself in these films and other photographs.6
Importantly, McLain testified that his motorcycle radio had a chronic
problem with a sticky microphone relay. Of equal importance, McLain
recalled that he was in Dealey Plaza on Houston Street between Main and
Elm streets when he first heard the gunfire.7 The former patrolman also
testified that he followed the motorcade on to Parkland Hospital after the
shooting, and in fact, personally assisted Jacqueline Kennedy out of the
presidential Iimousine.8 His testimony on all counts was consistent with the
sounds on the DPD tapes, and, McLain's motorcycle was the only unit that
was in a position in the motorcade to have been at the acoustically defined
locations at the time of the shooting.

When McLain testified to the Assassinations Committee in 1978 his
testimony was supportive of the evidence on the police recordings. But over
time McLain came to recant his statements. In contradiction to his sworn
testimony, McLain later protested that his could not have been the
motorcycle with the open microphone. He would not have been tuned to the
wrong channel, he argued, and what's more, he now claimed, he did not even
proceed with the motorcade to Elm Street but had stopped on Houston
Street.9 Consequently, much of the dispute over McLain's location derives
from his memory of events.

Aside from McLain's account, all of the critics who have asserted that his
motorcycle was not at the acoustically required locations rely on an
erroneous time-line of the gunfire relative to the Zapruder film. . . .

The television documentary sponsored by ABC News entitled "Beyond
Conspiracy," relied on, but did not show, a computer animation of the "Leon
Zapruder" film, which it erroneously billed as the "only known film of the
murder." It touted the digital simulation of the assassination as providing
"concrete evidence" that refuted the acoustical analysis. Actually, the
computer simulation was developed by a known critic of JFK conspiracy
theories named Dale Myers, the author of a book on the Tippit murder.
Myers' analysis included several amateur films, but in particular the Hughes
film18 which showed McLain just before the shooting. Myers concluded that
the last frame showing McLain, at a distance of 174 ft south of the first
acoustically required location, corresponded to a point in time only a half
second before the first shot. If that were true then McLain would have had to
travel in excess of 200 mph to arrive at the requisite spot in time.

Unfortunately, the ABC documentary, first airing in 2004, was well into the
rerun phase before the details of Myers' analysis were made available by him
in 2007.19 Following the release of the documentary in 2004 an ad hoc group
of researchers attempted to duplicate Myers' analysis by synchronizing the
Hughes and Zapruder films. The group failed to reach a firm consensus, there
being no direct connection found between the films. As did Hughes,
Zapruder had filmed a sequence, stopped, and filmed another. The first 132
frame sequence of Zapruder's film anticipated the President's arrival.
Zapruder stopped filming, then began anew at frame 133 with the
Presidential limousine already on Elm Street. The end of the Hughes film,
and the beginning of the Zapruder sequence, both show Car-5 entering the
intersection at Elm and Houston. Thus, the Hughes sequence with McLain
appears to start at about the same time that Zapruder's sequence begins, plus
or minus a couple of seconds. These seconds are crucial.

Because there are no depicted events indisputably common to both films, the
key to establishing synchronization between the Hughes film and the
Zapruder film are the motorcade vehicles, such as Car-5, but also the press
cars on Houston Street. Because the press cars are in all instances further
along the route in the Zapruder film than they are in the Hughes film, the real
variable, and in essence the critical unknown, was the speed of the motorcade
during the un-filmed interval. The Hughes film is discontinuous. One
sequence shows the presidential limousine turning on to Elm Street from
Houston. The next sequence consists of 72 frames (about four seconds) that
show McLain traversing the intersection at Main and Houston (Fig. 18.5).
McLain appears in the middle two seconds of the filmed sequence. . . .

If Hughes' memory is accurate, then McLain had around six seconds to reach
the first acoustically identified position about 174 feet away from where he is
last seen. But, of course, eyewitness estimates of short lengths of time can be
inexact and one cannot rely on their memories as providing definitive
evidence. That is, Hughes' guesstimate of five seconds may easily have been
off by a few seconds at least. To frame the issue in a more exact perspective;
at a speed of I 0 mph, which equals 15 ft per second, McLain needed about
11 seconds to reach the acoustically specified position. But at 20 mph (30 ft
per sec) he could have covered the distance in only five and-a-half seconds,
in accord with Hughes' memory. Or, at speeds between 21-29 mph, McLain
could have covered the distance in as little as 3-5 seconds. Thus, in order to
conclude that the filmed evidence provided "concrete" proof refuting the
acoustical evidence one would have to prove that the Hughes film was
exposed less than a few seconds before the first shot. For the ABC
documentary, Myers had calculated that interval as only a half second. . . .

Another key assumption made by Myers was that during the un-filmed
interval between the Hughes and Zapruder film, the motorcade on Houston
Street had traveled at a steady, even pace of around 9 mph. Indeed, Car-8 can
be seen moving for an instant in the Zapruder film in the vicinity of frame
220 and its speed was around 9 mph. At that point it was about 56 ft north of
where it was seen in the Hughes film and if it had maintained a speed of 9
mph then McLain would have had Jess than two seconds to reach the
acoustically defined position. But how reliable was the assumption that the
instantaneous speed could be extrapolated over several car lengths, given that
the cars ahead were traveling slower? In particular, the Secret Service car
(Car-5) is seen in the Hughes film at the head of the column as it begins its
tum on to Elm Street. In the Zapruder film the front bumper of Car-5 comes
in to line with a lady dressed in red standing on the comer at Z-144. The
corresponding rear bumper reaches the lady in red exactly 34 frames later at
Z-178. Thus, at 18.3 frames per second it took the car 1. 9 seconds to go one
car length. The hard-top Mercury had a length of 215 inches, about 17.9 ft,
thus it had a speed of 9.4 ft per second, which equals 6.4 mph. How could the
cars behind it sustain a 40% greater velocity?

Clearly, it is much more likely that the cars were moving in accordion-like
fashion caused by slowing through the turns and speeding up in the
straightaways as the speed measurements indicate. Moreover, speeds of 6-9
mph would be achieved as much if not more by applying the brakes than the
accelerator, resulting in a slow and surge motion. That in fact, is the way the
police officers remembered it. . . .

The "coaches in a train" analogy is an accurate description of the model used
by Myers' for his animation. The point is that in this crucial analysis Myer's
had relied on inference and assumptions, not measurements. Actual
measurements show that the cars slowed through the turns and sped up on the
straightaways. A better inference would be, as anyone with experience with
traffic jams knows, those in the back of the pack slow much more than those
in front.

But it was not just the speed of the motorcade that Myers' had inferred, it
was the position of the cars. The exact position of Car-S as depicted in the
Hughes film was particularly ambiguous. It was one of the contentious points
that the ad hoc group had been unable to satisfactorily resolve. Myers
claimed to have used an exacting process, labeled "epipolar geometry," to
position the cars in his animation. Epipolar geometry is a method of stereo
imaging. To do stereo imaging one has to have two different camera views of
the same object, in this case, the cars on Houston Street. But because the
objects are in motion, the stereo pair analysis requires that they be
photographed at the same time, not at different times at different places.
More importantly, the "epipole" in the analysis is the depiction of the
opposing camera in each respective image of the object being measured. But
at no point does Zapruder appear in the Hughes film nor does Hughes appear
in the Zapruder film. So there are no epipoles and therefore no epipolar line
which is the baseline used in the triangulation process of an epipolar analysis.
Meyers had not done an epipolar analysis, at least not in the key analysis
involving the location of the cars on Houston Street.

Inasmuch as Myers could not have done as exacting an analysis as he had
claimed he had done, exactly how had Myers located Car-5 on Houston
Street. Presumably Myers had used simple "line of sight" procedures to align
the cars as seen in the Hughes frames with inanimate landmarks in the
camera's view in order to fix their positions on Houston Street. But the
accuracy of such procedure depends heavily on an accurate placement of said
camera. And while Zapruder's position was known, Hughes' position was
not. Although Myers' cites an exact position for Hughes at precisely 15.5 ft
west of the center line of Houston Street and 8.8 ft south of the center line of
Main Street, this was another inference and not one fixed by photographic
evidence. Researchers have yet to find a photograph depicting Hughes.
Although there is a consensus among analysts that Hughes was in line with
the middle of the three lanes of east bound traffic on Main Street, Myers had
arbitrarily placed Hughes in line with the inner most traffic stripe, that is, as
far north as might reasonably be inferred. Others have placed Hughes on the
opposite side of the lane, 11 ft away. Shifting Hughes' position northward
similarly shifts the projected position of the cars to the north, and effectively
shortens the timeline.

Through this combination of error (the timing of the first shot) and inferences
favorable to his thesis (on the speed and position of the cars) Myers made it
appear that McLain had only about one half of a second to cover the 174 ft
between his last filmed location and the acoustically required position.
Applying the actual speed of the cars of about 6-9 mph (about two seconds to
travel a car-length), and setting the cars only a half car length further south
adds about two seconds to the timeline, giving McLain about 3.5 seconds to
reach the specified location, requiring an average speed of 33 mph rather
than the 400 mph claimed by Myers. However, these calculations assume the
"coaches in a train" model for the motorcade. If the cars were slowing and
surging as the escort patrolmen remembered, then McLain had even more
time to reach the required location. Ultimately, the Hughes film only proves
that McLain was in a position some several seconds before the first shot such
that at a reasonable rate of speed he could have been in the right place at the
right time. In the Hughes film his motorcycle is traveling at 14.7 mph as he
made the turn from Main on to Houston, much faster than the cars in the
motorcade, and one might presume that he would speed up as he came out of
the turn. In that regard one has to consider again the information in the
Zapruder film. McLain either sped up, and caught up to Car-6 near the
intersection, or he slowed down to stay next to Car-l 0. And because Myers
had aligned the first shot to Z-frame-160 instead of the correct Z-175, the
critical information regarding the juxtaposition of the Mayor's car, sixth in
line, to the acoustically identified locations was also missed. This car was
particularly important in relating yet another film to the acoustical
hypothesis.

This film was shot from inside the book depository by an employee named
Elsie Dorman. The Dorman film shows a motorcycle cop arriving at the
intersection of Elm and Houston just ahead of the eleventh car in the
motorcade (Fig. 18.6). Because this motorcycle is in the same juxtaposition
with respect to the motorcade as McLain was in the Hughes' film, some
researchers jumped to the conclusion that it must be McLain. But
synchronizing the Dorman film to the Zapruder film shows that this
conclusion was premature. Moreover, whereas the Dorman film does not
show the positions where the suspect motorcycle was supposed to be, it
shows virtually all of the area where it was not supposed to be, and thus by
the process of elimination, indicates that McLain could only have been where
the acoustical evidence required; provided that the patrolman in the film is
not McLain.

The Dorman film is a discontinuous film with at least four sequences
showing the motorcade. Dorman was in a window on the fourth floor of the
book depository such that she was looking down on the signal light
controlling traffic at the intersection (Fig. 18.7). In one critical sequence the
film shows a portion of the motorcade on Elm Street ending just as the fifth
car in the line, the Secret Service car, enters from the left. Exasperatingly, the
predicted motorcycle position at that time was just behind Car-5. When she
resumed filming, Dorman's next sequence begins with the camera's view in
the same location but now shows the back half of Car-6, the Mayor's car, on
Elm Street, directly underneath the signal light. Thus maddeningly, the film
does not show the area of the street between Car-5 and Car-6 which is
exactly where McLain is predicted to be. This sequence lasts about seven
and-a-half seconds during which Dorman panned left towards the
intersection. Five seconds into this sequence a motorcycle cop appears and
over a 40 frame interval (about 2.5 sec) can be seen on Houston Street
arriving at the intersection with Elm. If the cop is McLain he is clearly out of
position and the acoustical evidence is invalidated just as Myers claims. But,
there is nothing in the physical appearance of the cop, or his motorcycle, that
would definitively identify him as McLain as opposed to the other possibility
that it is J.W. Courson, who was the next patrolman behind McLain. Here the
timing is again crucial. . . .

Both patrolmen, McLain and Courson, recounted seeing the incident with
Mrs. Kennedy and the Secret Service agent on the trunk of the car;
understandably an event that would have stuck in their memories, even if the
timing or sequence of events might not have. The officers had to have been
on Elm Street to have witnessed this event. McLain's revised version of
events in which he claimed that he saw Mrs. Kennedy on the trunk when he
had stopped on Houston Street half way between Main and Elm is thus
directly contradicted by the filmed evidence. If the cop in Dorman is
McLain, obviously he had not stopped on Houston Street, at least not at the
time that Mrs. Kennedy was on the trunk of the car as he recalled; and if the
cop is Courson, then McLain was even further down Elm Street because
Courson was behind him. In this regard, Courson's account is compelling.

"The limousine came to a stop and Mrs. Kennedy was on the back.
I noticed that as I came around the corner at Elm."22

Thus, Courson's account (not McLain's) is consistent with the timing of
events in the Dorman film, but only if the officer depicted is Courson. Of
course, no eyewitness memory can be taken as definitive. Rather it is the
hard evidence of the films that counts. And in that regard the Dorman film
provides another clue. If the officer in Dorman's film is Courson, then
McLain could only have been exactly where the acoustical evidence requires.
That is, just ahead of the Mayor's car as it is located at the start of the critical
sequence of the Dorman film.

In the end, the amateur films of the motorcade in Dealey Plaza are definitive
on the acoustical evidence only to the extent that McLain's motorcycle was
either in exactly the right place at the right time, in the vicinity of the
Mayor's car, or way back in the motorcade, and nowhere close. Assertions
to the contrary are based on unsupported inferences and miscalculations. The
ABC documentary's "concrete evidence" had feet of clay. The producers had
relied on an expert23 whose only credential was a bias against conspiracy
theories. Lost among the media hype and miscalculations is the simple fact
that the filmed evidence shows that there was a motorcycle in a position on
Houston Street before the shooting and on Elm Street after the shooting such
that at a reasonable rate of speed would have been in the acoustically
required locations; and that the only motorcycle that could have been in the
right locations, happened to be the one that had a problem with a sticky
microphone. (Hear No Evil, 2010, pp. 667-685)

[Walt Cakebread]

Erm...as I understand it Julia Ann Mercer never even heard the shots so how could she have her testimony changed regarding how many shots there were?

Go easy with the scorn 

I was referring to a  witness who said that the authorities altered her account of what she had seen and reported.  And there are many of them....But Mercer immediately popped into my mind.

[Walt Cakebread]

The paragraphs below are segments from chapter 18 of the first edition of Dr. Thomas’s book Hear No Evil (2010). Chapter 18 deals with the identification of the patrol bike with the open mike. Dr. Thomas spends considerable time in that chapter dealing with Dale Myers’ research on the position of McClain’s bike. To get the full impact of Dr. Thomas’s arguments, you need to read the entire chapter, because, as mentioned, the paragraphs below are only some of the paragraphs in the chapter.

Wow!!..... How can you keep track of the motorcycles and vehicles  

[Dan O'meara]

I was referring to a  witness who said that the authorities altered her account of what she had seen and reported.  And there are many of them....But Mercer immediately popped into my mind.

Yeah Walt, but I was specifically asking about the testimony of those who heard three audible shots during the assassination. There are over 160 such witnesses and Michael would have us believe that, because there is evidence of some witnesses having their testimonies altered - Mercer may be an example - then we can assume that this overwhelming majority of witnesses who heard three audible shots also had their testimonies tampered with.
Michael has to come up with this  because it is hard evidence that utterly refutes his wobbly theory that was so thoroughly demolished in his own thread -  "Reactions to 6 Shots in the Zapruder Film".
You have misread what I've posted or misunderstood it but if you have any scrap of evidence that any of the 160+ witnesses who report hearing three shots have had their testimonies altered in this specific respect please let me know.
If you are unaware of a single instance you must surely conclude that this nonsense assertion by Michael is false, that the vast majority of witnesses did indeed hear three shots and that this indisputable, hard evidence makes a mockery of Michael's claims to five audible shots during the assassination

[Walt Cakebread]

Yeah Walt, but I was specifically asking about the testimony of those who heard three audible shots during the assassination. There are over 160 such witnesses and Michael would have us believe that, because there is evidence of some witnesses having their testimonies altered - Mercer may be an example - then we can assume that this overwhelming majority of witnesses who heard three audible shots also had their testimonies tampered with.
Michael has to come up with this  because it is hard evidence that utterly refutes his wobbly theory that was so thoroughly demolished in his own thread -  "Reactions to 6 Shots in the Zapruder Film".
You have misread what I've posted or misunderstood it but if you have any scrap of evidence that any of the 160+ witnesses who report hearing three shots have had their testimonies altered in this specific respect please let me know.
If you are unaware of a single instance you must surely conclude that this nonsense assertion by Michael is false, that the vast majority of witnesses did indeed hear three shots and that this indisputable, hard evidence makes a mockery of Michael's claims to five audible shots during the assassination

the vast majority of witnesses did indeed hear three shots and that this indisputable,

Yes,  you are absolutely right.... I'd say that about 98% of the witnesses who heard the explosions reported that they heard three shots....Although a significant number of them said they weren't sure that the first explosion was a rifle shot....

I'm sure that there were at least five shots fired ( maybe more) but a couple of the shots were inaudible....

[Pat Speer]

Dr. Thompson feels that Dr. Thomas has already sufficiently dealt with the issue of the photographic evidence regarding McClain's location.

https://www.maryferrell.org/pages/Essay_-_The_Bike_With_the_Mike.html

https://www.maryferrell.org/pages/Essay_-_Debugging_Bugliosi.html

Dr. Thompson's approach is to show that the dictabelt recording absolutely, positively contains at least four gunshot impulse patterns that were recorded in Dealey Plaza during the assassination, and that one of the shots came from the grassy knoll. So someone's microphone in Dealey Plaza recorded those gunshots, whether it was McClain's, Beilharz's, Price's, or someone else's mike. Personally, I find Dr. Thomas's research on the bike with the mike convincing. 

The gunshot impulse patterns match the unique patterns of gunshots fired in Dealey Plaza. They have the echo speed and locational characteristics of shots that were fired in Dealey Plaza and that were recorded by a motorcycle moving in Dealey Plaza. Dr. Aschkenazy put it this way:

I think it would be helpful to keep in mind that even the NRC panel admitted that there was only a 7% probability that the numerous locational correlations between the dictabelt gunshots and the test-firing gunshots were the result of chance (https://miketgriffith.com/files/hscaacous.pdf, pp. 12-13).

As for the argument that the vast majority of plaza witnesses said they heard three shots and that therefore this disproves the acoustical evidence, it is hard to believe that anyone is still pushing this patently silly, lame argument after all we now know about how the FBI and the DPD manipulated the eyewitness accounts, given that we now know that the shots in two shot groups came within fractions of a second of each other, and given that the Zapruder film plainly and clearly shows reactions to at least five shots.

https://miketgriffith.com/files/6shots.htm

The acoustics experts didn't just say the tape demonstrated four or more shots, they stated the tape picked up these shots from specific locations within the plaza at specific times. The HSCA said the bike with the mic was McLain's, and Thomas agreed.

The Z-film, Dorman film and Hughes film prove, however, that McLain was not where the HSCA said he was when the first shot was fired.

As a consequence, Thomas moved back the time of the first shot to frame 175.

But the Wiegman film and Bond 4 prove Wiegman--who was supposedly 2 cars behind McLain at the time of the first shot--was on the knoll for 7 seconds or more before McLain passed him by. Well, this makes no sense, seeing as he was on foot, and McLain was on a motorcycle.

I pointed this out to those working with Tink on his book early last year. It was too big a problem to overcome, and was subsequently ignored.

Upon reading Tink's book, moreover, it's easy to see why. He spends much of the book going after the Ramsey Panel and Alvarez specifically. And he's probably right to do so. That they may have been correct about the sounds on the tapes not being shots, to be clear, shouldn't lead us to forgive the deceptions Tink discovered in the working papers provided by Hoch. 

As stated, my hope was Tink would find a way for the shots to be legit without their being recorded by McLain. I am disappointed that this was not done.

[Dan O'meara]

the vast majority of witnesses did indeed hear three shots and that this indisputable,

Yes,  you are absolutely right.... I'd say that about 98% of the witnesses who heard the explosions reported that they heard three shots....Although a significant number of them said they weren't sure that the first explosion was a rifle shot....

I'm sure that there were at least five shots fired ( maybe more) but a couple of the shots were inaudible....

Just out of curiosity Walt, what makes you sure there were inaudible shots?

[Michael T. Griffith]

Quote from: Walt Cakebread on Today at 03:59:00 AM

the vast majority of witnesses did indeed hear three shots and that this indisputable,

Yes,  you are absolutely right.... I'd say that about 98% of the witnesses who heard the explosions reported that they heard three shots....Although a significant number of them said they weren't sure that the first explosion was a rifle shot....

I'm sure that there were at least five shots fired ( maybe more) but a couple of the shots were inaudible....

Just out of curiosity Walt, what makes you sure there were inaudible shots?

It is astonishing to see anyone still arguing that there were only three shots because most of the witnesses reportedly only heard three shots, given that we know that the FBI and the DPD distorted what witnesses told them, given that some of the shots were fired nearly simultaneously and thus could have sounded like a single shot, given the accounts of extra shots hitting grass and pavement in Dealey Plaza (and some of those accounts are supported by photographic evidence), and given that the Zapruder film clearly shows reactions to six shots.

As for McClain, I quote from my article on the acoustical evidence:

Another claim that McClain made after he gave his HSCA testimony was that while he was still moving on Houston Street, he saw Mrs. Kennedy climb onto the trunk of the limousine. If true, this would put him in locations different from those indicated by the dictabelt recording at key times. However, McClain’s claim is unlikely. We know that Mrs. Kennedy climbed onto the limo’s trunk no more than 5 seconds after the final shot. Intervening crowds of people and structures would have been made it difficult for McClain to have seen Mrs. Kennedy on the trunk from Houston Street. But, if McClain was where the acoustical evidence places him at this time—on Elm Street—then he would have had a clear view of Mrs. Kennedy’s actions. Moreover, Patrolman Jimmy Courson, who was at least 40 feet behind McClain, said he saw Mrs. Kennedy on the trunk just as he was turning onto Elm Street. It appears that McClain changed his story in ways that would disqualify his motorcycle as the one whose mike recorded the sounds on the dictabelt tape. (https://miketgriffith.com/files/hscaacous.pdf)