Friday, November 19, 2010

JFK Assassination Acoustics and the Photographic Record: Why the HSCA’s Acoustic Evidence of Conspiracy is Invalid

by DALE K. MYERS

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In 1979, the House Select Committee on Assassinations (HSCA) concluded that there was a “high probability that two gunmen fired at President John F. Kennedy,” and therefore, Kennedy was “probably assassinated as a result of a conspiracy.” [1]

Their conclusion, which contradicted the 1964 Warren Commission’s conclusion that Lee Harvey Oswald alone killed President Kennedy, was based largely on an acoustical analysis of an eight-second segment of a Dallas police recording made of radio transmissions presumed to have originated from a motorcycle within the presidential motorcade.

Although the static-filled recording contained no audible sounds that could be distinguished as being gunshots, two acoustic research groups concluded that the recording contained four impulse sounds, which they believed were probable gunshots.

According to these experts, three of the “gunshots” were fired from the sniper’s nest on the sixth floor of the Texas School Book Depository, while a fourth “gunshot” originated from the infamous grassy knoll. [2]

The acoustic experts also predicted that the motorcycle with the open microphone was located 120 to 140 feet behind the presidential limousine at the time of the shooting.

After a limited review of the photographic record, the HSCA identified the motorcycle officer with the open microphone as Dallas police officer H.B. McLain, who the committee alleged was “in the approximate position of the transmitting microphone, as indicated by the acoustical analysis,” and therefore was responsible for transmitting the gunshot sounds. [3]

The importance of the HSCA’s acoustic evidence cannot be over emphasized. It is the only hard, physical evidence ever offered in support of a conspiracy over the course of the nearly five decade assassination debate. Without it, there is no credible reason to believe that anyone other than Lee Harvey Oswald fired shots at the Kennedy motorcade.

It is equally important to recognize that the conclusions of the HSCA acoustic experts hinge on a very basic assumption – a police motorcycle, with an open microphone, was transmitting the sound of the gunshots from four very specific locations at the time of the assassination. In order for the HSCA’s acoustic evidence of conspiracy to have validity, a police motorcycle must be present at the four specific locations and times predicted by the acoustic analysis. If there is no motorcycle at the location and times predicted by their analysis, their conclusions are, by default, invalid – plain and simple.

Dr. James Barger, lead scientist with the acoustic team at Bolt, Beranek and Newman, Inc. (BBN) said as much in 2001, “…if it can be shown that there was no vehicle or person with a police radio near the trajectory where I found it to be, then, that is impeaching evidence.” [4]

G. Robert Blakey, Chief Council of the HSCA, told ABC News the same thing in 2003, “If you could prove to me that there was no police officer in the place where he had to be, you would falsify [the acoustics evidence].” [5]

In 2007, I released a graphic report – Epipolar Geometric Analysis of Amateur Films Related to Acoustics Evidence in the John F. Kennedy Assassination – detailing my study of photographic evidence related to the acoustics issue. That 179-page report documented the use of computer technology to construct a synchronized photographic record of the shooting and determine the validity of the acoustic evidence.

That study proved beyond all doubt that neither H.B. McLain nor any other motorcycle officer was in a position to transmit the sound of gunshots over the Dallas police radio system as the HSCA postulated and consequently the committee’s acoustic evidence of a conspiracy in the Kennedy assassination is invalid.

Nine months after the release of my graphic report, entomologist and part-time conspiracy theorist Donald B. Thomas, whose Science & Justice article “Echo correlation analysis and acoustic evidence in the Kennedy assassination revisited” grabbed headlines in 2001, promised to show that “the study by Myers contains serious errors that invalidate his conclusions” in an Internet article entitled, “The Bike with the Mike.”

Mr. Thomas’ promise turned out to be nothing more than a series of falsehoods and mischaracterizations that only managed to expose the faults and contradictions in his own hypothesis. All of it was detailed in the April, 2008, blog post, “Photographic Proof: H.B. McLain and Acoustics.”

Hear No Evil

Now comes Mr. Thomas’ masterwork, Hear No Evil: Social Constructivism & The Forensic Evidence in the Kennedy Assassination (Mary Ferrell Foundation Press, 2010), a 767-page tome that attempts to tackle all forensic aspects of the Kennedy assassination and presumably gives the entomologist yet another chance to address the serious problems with his acoustic hypothesis.

Those expecting a spirited rebuttal to the contradictions and gaffes I found in Mr. Thomas’ “Bike with the Mike” article will be disappointed.

Rather than addressing the problems raised by his 2008 article, Mr. Thomas simply restates them, lifting large extracts from the earlier article, as if there was no problem.

But, oh there is a problem – a very big problem and Thomas knows it.

The Bike with the Mike

Mr. Thomas understands very well that the photographic record is the heart and soul of the validity of the acoustics evidence for conspiracy in the Kennedy assassination.

Thomas acknowledges as much when he writes, “The filmed evidence provides a test of the acoustical hypothesis, in that a motorcycle with a stuck microphone had to have been where the test microphones recorded the matching test patterns at the actual time of the shooting.” [6]

A few pages later, Thomas postulates that “… McLain had to have been near Car-6 [the Mayor’s car], in which case he was exactly where the acoustical evidence predicts, or, he was back near Car-10 [Camera Car 3], in which the acoustical hypothesis is falsified.” [7]

And still later, Thomas reiterates 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 no where close.” [8]

Mr. Thomas obviously believes that McLain’s motorcycle is near the Mayor’s car, a position that would be in accord with the acoustics evidence if it were true. So, what evidence does Thomas offer that McLain is exactly where the acoustics evidence predicts?

Nothing. Nada. Zip. Thomas argues that since no photographs or films show the area of the acoustic zones at the exact moment of the shots there is no photographic evidence to prove that McLain could not have been there as predicted.

That’s right, for Thomas, the lack of photographic evidence for his hypothesis is the evidence.

But of course, there is abundant photographic evidence that McLain is nearly a block from the acoustically required position and so Thomas is forced to spend eighteen pages attempting to knock down that evidence any way he can in order to keep the acoustic fantasy of conspiracy alive.

I have no intention of detailing (once again) every falsehood, mischaracterization, and outright lie about my efforts to reconstruct the photographic record that Mr. Thomas attempts to put over as fact in his book Hear No Evil.

Mr. Thomas’ acoustic fairy tale was all laid bare and demolished two years ago in the blog post, “Photographic Proof: H.B. McLain and Acoustics.”

But here are a few of the salient arguments rehashed by Thomas in the new book, and the truth of the matter.

Making Assumptions

“… built into Myers’ reconstruction was the assumption that the grassy knoll shot had missed, and thus he had placed the first acoustically determined shot as equivalent in time to Z-160 instead of Z-175. Resetting the first shot to Z-160 had the effect of lopping nearly a full second off of the time that McLain had to reach the acoustically required position.” [9]

Nonsense. Nothing was assumed in my analysis of the photographic record as it related to acoustics. As many people who have seen my work can attest, I lifted every rock, turned over every stone, and covered all the bases in spades – well above and beyond what would be required to make the point.

And as Thomas well knows, I set about testing the acoustic theory proposed by the HSCA, not the theory postulated by Don Thomas of Texas.

The HSCA concluded that four shots were fired at the equivalent of Zapruder frames 160, 196, 309, and 312. It was Thomas’ own resurrection and resynchronization of the original data that produced a new theory that five shots were fired at the intervals Z175, 204, 224, 313, and 326.

But here again, Thomas ignores the fact that the photographic record also fails to support his own five shot theory, as I pointed out in my 2007 report and again in my 2008 rebuttal to his article, “The Bike with the Mike.”

Thomas offers no argument in Hear No Evil because he has none to give.

Steady as She Goes

“… Another key assumption made by Myers was that during the un-filmed interval between the Hughes and Zapruder film, the motorcade on Houston Street traveled at a steady, even pace of around 9 mph.” [10]

This is a lie easily refuted by my 2007 report and again in my 2008 rebuttal to the same charge made in “The Bike with the Mike.” Read them.

Case in point, it is demonstrated in the report that the National Press car was moving at 9.5 mph during an unseen interval of 1.48 seconds, [11] that Camera Car 1 was moving at 8.7 mph during an unseen interval of 2.73 seconds, [12] and that Camera Car 2 was moving at 8.1 mph during an unseen interval of 3.28 seconds. [13]

Contrary to Thomas’ assertion, the motorcade is traveling on Houston Street at an uneven pace between 8.1 and 9.5 mph.

You’ll note that the time these vehicles are off camera is very short (between 1.48 and 3.28 seconds).

Mr. Thomas argues that a “snapshot” of the speed of these motorcade vehicles as seen in the Hughes film and their reappearance in the Zapruder film a few seconds later cannot be applied to the interval between the two films (Thomas calls this “an untestable assumption” in his 2008 “Bike with the Mike” article).

But Thomas fails to take into account that both films depict the motorcade moving north on Houston Street in a continuous fashion.

The motorcade is made up of a procession of vehicles, one following the other in a single line, as they make their way along the parade route in an undulating fashion. Even if some of the vehicles move off camera, we can be assured that they are continuing to move forward (and not stopping or slowing significantly, as Thomas suggests) simply because the vehicles which are in the camera’s view are seen moving forward in a normal manner.

And let’s not forget we are talking about a few seconds of time during which some vehicles are off camera, not minutes.

Thomas also argues that a vehicle moving at “an even pace of around 9 mph” cannot “sustain a 40% greater velocity” than a car ahead of it that is slowing to make the turn onto Elm Street. [14]

Here Thomas uses the Vice-Presidential Secret Service Follow-up Car as an example, claiming that it was only traveling at 6.4 mph as it made the turn (actually it was traveling at 7.0 mph as I pointed out in 2008). How then, Thomas argues, could the vehicles behind it sustain a 40% greater velocity?

The answer is obvious, they don’t sustain their velocity. They slow down just as all the vehicles do as the approach the turn onto Elm Street.

The Vice-Presidential Secret Service Follow-up Car is more than 70 feet ahead of the motorcade vehicles Mr. Thomas uses for comparison and well into the Elm Street turn. Six seconds will elapse before the trailing vehicles reach that same point in the turn.

Obviously there is enough time and distance for those trailing vehicles to decelerate from 9.0 to 7.0 mph.

Coaches in a Train

“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 Myers’ had relied on inference and assumptions, not measurements. Actual measurements show that the cars slowed through the turns and sped up on the straight-aways. 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 the front.” [15]

This is another lie, again, easily refuted by my 2007 report and again in my 2008 rebuttal to the same charge made in “The Bike with the Mike.” Read them.

There are many examples of variations in speed among the motorcade vehicles presented in my report, and no doubt many more demonstrative examples available in the filmed record, assuming one has the inclination to measure and make the calculations.

All of these measurements show the motorcade vehicles accelerating and decelerating at various speeds independent of each other as one would expect in a motor vehicle parade of this type.

Ad Hoc Reasoning

“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-5 [the Vice-Presidential Secret Service Follow-up Car] 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.” [16]

Mr. Thomas explains that “Following the release of the [ABC] documentary in 2004 [17] 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.” [18]

Really? Who are the members of this ad hoc group of researchers? What are their qualifications? What was their methodology? What were their conclusions? We’re not told.

Earlier in his book, Thomas described the term “ad hoc” as “Latin for bullshit.” [19] I agree.

Epipolar Geometry

“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 use in the triangulation process of an epipolar analysis. Meyers (sic) had not done an epipolar analysis, at least not in the key analysis involving the location of the cars on Houston Street.” [20]

Rubbish. Mr. Thomas completely mischaracterizes my use of epipolar geometry in resolving spatial issues related to synchronizing the Zapruder and Hughes films.

Yes, epipolar geometry is a method of stereo imaging. It’s also useful in the field of architectural design (dating back to the Greeks), visual effects realization, and many other applications.

And yes, the ‘epipole’ is the imaginary baseline projected between the depiction of the opposing camera in each respective image of the object being measured, however, the ‘epipole’ does not necessarily need to be depicted in the image to resolve the equation. Mr. Thomas would know this if he’d spent more than a few minutes exploring Wikipedia before expounding on a subject he clearly knows nothing about.

In my 2007 report, I explained how the angle of the Secret Service car seen in the Hughes film was determined by aligning the film with a computer model of Dealey Plaza using a method known as triangulation, writing:

“Triangulation is a highly accurate way of computing the six degrees of a camera’s freedom based on camera footage. This technique is based on epipolar geometry and is used by many of the world’s foremost motion picture visual effects masters to seamlessly match computer generated imagery with live action footage. Through triangulation, it is possible to determine a camera’s position in 3D space by taking any film or video footage that a camera has recorded; superimposing that footage over a three-dimensional model of the scene recorded; and triangulating three or more fixed points that are visible within its field of view. Because the technique applies to any motion picture footage, historic events can be explored using this method.” [emphasis added] [21]

Two important footnotes accompany this text: (a) “Epipolar geometry describes the geometric relationship between two optical systems viewing the same subject and can be used to locate points or objects in space. Because a moving camera offers a new view every frame, epipolar geometry works for a single moving camera as well, and each new view is understood as a separate optical system;” and (b) “[The manual process I used] has been largely replaced in the last few years by camera match-moving software like RealViz’s MatchMover, 2D3’s Boujou, SynaPix’s SynaMatch, and Autonomous Effect’s CameraGenie.” [emphasis added] [22]

What Mr. Thomas fails to acknowledge is that a multi-billion-dollar-a-year visual effects industry has been built on the highly accurate and reliable ability to triangulate the three dimensional position of objects in space using epipolar geometry as the basis for modern software solutions.

The fact that epipolar geometry solutions work for a single moving camera is the basis for match-moving software (which allows computer generated objects to be inserted seamlessly into live action footage shot from a single camera source) and the essence of how I was able to take multiple individual camera positions and reconstruct a continuous and highly accurate geometric timeline of the assassination event.

And having spent literally thousands of hours perfecting a manual solution and later working with modern-day match-moving software solutions, I can tell you that even the slightest inaccuracy will result in errors (seen as “slippage” between live action footage and dimensional objects positioned in space in relation to that footage).

Mr. Thomas’ attempt to characterize my use of the term “epipolar geometry” as inappropriate, or that my geometric reconstruction is somehow inexact, or that my methodology was not grounded in the use of epipolar geometry based on a very narrow reading of the definition of the term ‘epipolar geometry’ or the application(s) of this mathematical science, is not only false and misleading, it’s a flat out lie.

More important, Mr. Thomas was aware of everything you just read because it was published two years ago in response to the first time he made this ridiculous accusation.

Fixing the Hughes Camera

“…how had Myers located Car-5 [VPSS] 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 procedures 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...” [23]

STOP right there. That’s a lie. I explained in my 2003 report that through triangulation, it was possible to determine a camera’s position in 3D space based on footage that it had previously recorded. Using computer software, the recorded footage can be aligned to a three-dimensional model of the scene recorded Aligning three or more fixed points that are visible within the camera’s field of view reveals the camera’s original position in 3D space. The exact location of the camera can then be extracted from the geometric model.

Hence, the camera position is not inferred, as Thomas charges, it is extracted directly from the photographic evidence. But then Thomas knew that since I wrote about it two years ago when I addressed this same accusation in Photographic Proof.

Incidentally, the use of “simple line of sight procedures” to fix objects in space isn’t any less accurate than Weiss and Aschkenasy’s use of pins, string, and a slide rule to fix the position of the motorcycle allegedly transmitting the sound of a gunshot being fired from the grassy knoll. [24] Sometimes the simplest approach is the best, you know?

“...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 north, and effectively shortens the timeline...” [25]

STOP. The Hughes camera position wasn’t “arbitrarily” placed anywhere. Its exact position was determined using the method described above. But even without using computer software, the alignment of the camera with the northern-most eastbound white road stripe is obvious from the Hughes film footage itself. [See, Figure 1]


Figure 1. Hughes frame H223 showing Hughes’ camera position to be in-line with the white road stripe (arrow) immediately south of the centerline.


Furthermore, shifting the Hughes camera position 11 feet south would put Hughes behind a line of spectators [See, Figure 2] obstructing his view of the motorcade – something we know didn’t happen based upon his film footage which shows a clear view of the motorcade.


Figure 2. Bronson slide depicting spectators ringing the turn at Main and Houston.

Bottom line? Thomas is wrong again. But then he knew that two years ago when I made these very same points in Photographic Proof.

Circles on a Map

On page 671 of Hear No Evil, Mr. Thomas shows us a map of Dealey Plaza with five circles representing the location of the motorcycle at the time of each one of the five “gunshots” designated by the acoustic evidence. [See, Figure 3] Thomas notes that to be in accord with the acoustical evidence the motorcycle with the open microphone had to have been within 9 feet of each test microphone.


Figure 3. Thomas map depicting acoustic zones.

That’s true. James Barger, lead scientist with Bolt, Beranek, and Newman, Inc. (BBN), testified that placing the test microphones 18 feet apart assured that the motorcycle with the open microphone, if one existed, could be located within 9 feet of any given test microphone by matching test shots with the Dallas police recording. [26]

But look at the map. The circles Thomas uses have an 18 foot radius, not the 9 foot radius dictated by Barger’s acoustics test. This is easily demonstrated by noting the size relationship between the circles on Elm Street and the street itself.

Elm Street is 40 feet wide, yet the circles drawn on this map cover nearly the entire width of the road. How is that possible if the circles are only 18 feet in diameter (i.e., have a radius of just 9 feet)?

The same holds true for the circles drawn at the intersection of Elm and Houston. Houston is 60 feet wide, yet clearly the circles drawn at the intersection have a radius larger than 9 feet. In fact, all of the circles on the Thomas map are the same size – 36 feet in diameter (i.e., having a radius of 18 feet) – twice the size dictated by Barger’s acoustic test.

Why does Thomas show these acoustic zones at twice the dictated size? He must know that these acoustic zones are too large, because another map he publishes on page 584 to depict the 36 microphone locations used for the BBN test shows the acoustic zones considerably smaller, in fact, closer in size to the 9 foot radius described earlier. [See, Figure 4]


Figure 4. Thomas map showing BBN mic positions and the acoustic zones for his five shot theory.

The effect of using circles twice the dictated size makes it appear as if the entire intersection is blanketed by the acoustic zone. According to the Thomas map, the motorcycle with the open microphone could be anywhere on the left side of the street and still get caught in the array of test microphones.

The reality is much different. Figure 5 shows the true size of the acoustic test zones (i.e., acoustic zones with a radius of 9 feet around each test microphone position). As you can see, the hypothetical path of a motorcycle passing through the required acoustic zones would have to pass impossibly close to (and in some cases cross into the immediate path of) the motorcade automobiles driving down the center of the street. How is that possible?


Figure 5. Computer reconstruction depicting acoustic zones corresponding to Thomas’ five shot theory.

In a related matter, Mr. Thomas uses a photograph taken by James Altgens at the equivalent of Zapruder frame Z255 [See, Figure 6] to support his contention that the motorcycle with the open microphone would have been just outside of Altgens’ field-of-view had it been following its predicted path through the acoustic zones. But that would only be true if the acoustic zones were drawn twice the size dictated by the acoustic test, as Thomas had done.


Figure 6. Full frame version of the Altgens’ photograph corresponding to Zapruder frame Z255.

Again, the reality is much different. Figure 7 shows the true size of the acoustic zone at test microphone array 2(11). According to Thomas, this microphone position matches a gunshot fired at the equivalent of Zapruder frame Z224. Assuming that a motorcycle with an open microphone could pass through the southern-most portion of the acoustic zone without colliding with any motorcade vehicles, the hypothetical trajectory path of the motorcycle would almost assuredly place it within the field-of-view of Altgens’ camera 1.7 seconds later.


Figure 7. Computer reconstruction of the motorcade at the equivalent of Z255 depicting test microphone position 2-11 (green), Altgens’ field-of-view (red overlay), and Thomas’ hypothetical motorcycle trajectory (yellow).


This is especially true given the location of the acoustic zones for the next two shots which lie directly ahead. In particular, take a look at the presumed location of the motorcycle at the time of the alleged grassy knoll “shot” as determined by Mark Weiss and Ernest Aschkenasy. [See, Figure 8]


Figure 8. Computer reconstruction of the motorcade at the equivalent of Z255 depicting the hypothetical motorcycle’s probable location (red arrows) and its presumed location at the time of the alleged grassy knoll shot.


Weiss and Aschkenasy pinpointed the location of the motorcycle with the open microphone as being 95 feet south and 27 feet west of the southeast corner of the Texas School Book Depository (plus or minus one foot) at the time of the initial muzzle blast. [27] The motorcycle traveled another 6 feet along the path of the motorcade before all the trailing echoes reached the microphone. [28]

Plotting these positions on a computer model of Dealey Plaza shows the Weiss and Aschkenasy location to be within the 9 foot radius of the BBN microphone location, as it should be. (Thomas shows the motorcycle position to be about 4 feet southeast of where Weiss and Aschkenasy place it.)

The point here is that because the motorcycle with the open microphone would need to be within the area of the center lane on Elm Street at the equivalent of Z224, if indeed the acoustics evidence is valid, and would need to maintain a forward trajectory that places it squarely in the center of the center lane at the time of the alleged grassy knoll “shot” (the equivalent of Z313 according to Thomas), then the motorcycle with the open microphone would almost assuredly be in the Altgens camera’s field-of-view in between those two points (the equivalent of Z255).

By showing the acoustic zones at twice their actual size, Thomas makes it appear at least equally likely that the motorcycle could have avoided Altgens’ camera lens.

The Zigzagging Motorcycle

The map on page 671 of Hear No Evil also includes Thomas’ proposed hypothetical path for the motorcycle with the open microphone. The path is represented by the small circles. [See, Figure 9] According to Thomas, the motorcycle would have hugged the south curb of Elm Street as it made the turn from Houston, ventured slightly into the center lane (at the time of the grassy knoll “shot”), then returned to the southern-most lane.


Figure 9. Section of Thomas’ map depicting acoustic zones (large circles) and the hypothetical path of McLain’s motorcycle (small circles). Letter ‘b’ marks the motorcycle’s presumed location at the time of the alleged grassy knoll shot.


Using circles that are twice as large as dictated by the BBN test to represent the acoustic zones, Thomas makes it appear that his hypothetical motorcycle path will pass through each of the appropriate zones as determined by BBN.

When the acoustic zone circles are rendered at the correct size, we see the problems that Thomas is trying to avoid. [See, Figure 10]


Figure 10. Computer reconstruction of the motorcade at the equivalent of Z255 depicting seven acoustic zones (large circles), Altgens’ field-of-view (red overlay), Thomas’ hypothetical motorcycle trajectory (small yellow circles), and the actual motorcycle path required by Thomas’ five shot theory (solid yellow line).


First, if the acoustic theory is correct, the hypothetical motorcycle would have to travel further north on Houston before making its turn onto Elm in order to pass through the acoustic zones for the first two “shots.” Remember, if the motorcycle with the open microphone doesn’t pass through these acoustic zones then BBN doesn’t get a match between their test gunshots and the impulse sounds on the Dallas police dictabelt recording.

Traveling further north on Houston puts the hypothetical motorcycle on a collision course with the motorcade automobiles making the left turn onto Elm Street. The position of these automobiles is well established by the photographic record.

Traveling further north also means that the hypothetical motorcycle will not be hugging the south curb of Elm Street as Thomas postulates. The motorcycle would have to swing left in a much wider arch.

Second, the hypothetical motorcycle would have to enter the southern-most portion of Elm Street’s center lane in order to pass through the acoustic zone for microphone 2(11) – the BBN microphone position that Thomas contends matches the gunshot fired at the equivalent of Z224.

The acoustic match for this microphone position was rejected by BBN as a false alarm. Thomas resurrects this false alarm in order to have a “gunshot” that synchronizes with the reactions of Kennedy and Connally at Z223-224. This was necessary because Thomas is also postulating, in opposition to the HSCA, that the acoustic grassy knoll “shot” synchronizes with the head shot.

But if Thomas’ theory is correct, and the hypothetical motorcycle with the open microphone entered the acoustic zone designated by the test microphone at 2(11), the motorcycle would be on a potential collision course with either the Vice Presidential Secret Service Follow-up Car or the car containing Mayor Cabell and his party.

Both options seem dubious at best especially considering the fact that the hypothetical motorcycle could easily avoid both potential calamities by simply adjusting the sweep of its turn.

That, of course, is Thomas’ problem. If his hypothetical motorcycle does the obvious thing (i.e., avoids crashing into the motorcade vehicles traveling to his right) then it cannot pass through the appropriate acoustic zones at the required time in order to match the BBN test shots.

Third, as discussed earlier, Thomas’ hypothetical motorcycle must dart sharply south by Z255 to avoid being caught in the field-of-view of still photographer James Altgens’ camera lens.

Finally, the hypothetical motorcycle must cut back to the center of the middle lane – entering the path occupied by automobiles traveling in the motorcade – in order to be in position to pick up the sound of the last two shots. [See, Figure 11]


Figure 11. Computer reconstruction of the motorcade at the equivalent of Z313 depicting seven acoustic zones (large circles), Thomas’ hypothetical motorcycle trajectory (small yellow circles), and the actual motorcycle path required by Thomas’ five shot theory (solid yellow line).


You’ll note that Thomas’ hypothetical motorcycle path actually fails to pass through the acoustic zones designated for test microphones 2(5), 2(6), and 2(11) when the zones are scaled to their proper 9 foot radius. These positions equate to “shots” 1, 2, and 3 in Thomas’ five shot scenario. [See, Figure 10]

However, his hypothetical motorcycle path does pass through the acoustic zones for test microphones 2(8) and 2(10). Yet, no matches between the Dallas police dictabelt recording and the BBN test shots were obtained for the test microphone at position 2(8) and only one match with a low correlation coefficient was obtained for the test microphone at position 2(10). That match actually corresponded to the second “shot.” [29]

It should be obvious by now that the hypothetical motorcycle path proposed by Thomas contradicts his own data.

If you’re buying Thomas’ snake oil, then you also must buy into the idea of an out of control motorcycle zigzagging its way along the motorcade route – driving perilously close to the parade of cars (in order to pick up the sound of the first three “shots”), darting back toward the south curb of Elm Street (in order to avoid being seen by Altgens’ camera), then cutting back into the middle lane occupied by automobiles in the motorcade (to pick up the sounds of the final two “shots”).

Of course, doubling the size of the acoustic zones avoids having to deal with the zigzagging reality of Thomas’ hypothetical solution.

Direct Photographic Proof

It’s all pretty simple. Mr. Thomas cannot accept the simple truth that H.B. McLain couldn’t physically reach the position dictated by the acoustic evidence in the time allotted. Accepting that simple truth would kill the very thing he has fought to promote and defend for the last ten years.

He continues to hang his hat on what he calls “negative evidence” – that is, the so-called lack of photographic evidence that “McLain is not in the wrong position” to be the officer transmitting the sounds of gunshots. But, of course, this is demonstrably false.

Look, the photographic record is crystal clear on where McLain is immediately before the first shot. Hughes frames H631 through H648 show McLain’s motorcycle completing the turn from Main onto Houston – ending just as McLain’s front tire reaches the crosswalk.

Figures 12 through 14 depict a computer reconstruction of the motorcade at the equivalent of Hughes frames H631, H638, and H648 – a period of just 0.93 seconds.

Figure 12. Computer reconstruction of the motorcade at the equivalent of H631/Z133.

Figure 13. Computer reconstruction of the motorcade at the equivalent of H638/Z140.

Figure 14. Computer reconstruction of the motorcade at the equivalent of H648/Z150.

We know for a fact that these three Hughes frames align in time with Zapruder frames Z133, Z140, and Z150.

How do we know this? We know this for a multitude of reasons, supported by more than fourteen geometric and visual reference points: (1) The angle and position of the white 1963 Mercury Monterey (the Vice-Presidential Secret Service Follow-up Car) turning onto Elm Street forms a continuous motion path across both films, (2) five geometric reference points common to the Zapruder and Hughes films confirm the synchronicity between the Hughes and Zapruder films, and (3) nine additional visual reference points common to the Hughes, Towner, Dorman, Bell, and Martin films confirm the synchronicity between the Hughes and Zapruder films.

Ladies and gentlemen, there is absolutely no doubt that the last Hughes frame to show McLain’s motorcycle (H648) is equivalent in time to Zapruder frame Z150. This is not fantasy. It’s a fact.

And since the Zapruder film is a running clock on the assassination, we know that McLain has only 0.546 seconds to reach the acoustical zone for the first shot (assuming the first shot was fired at the equivalent of Zapruder frame Z160, as the HSCA concluded) or just 1.366 seconds to reach the zone (assuming the first shot was fired at the equivalent of Zapruder frame Z175, as the Mr. Thomas contends). [See, Figure 15]


Figure 15. Computer reconstruction of the motorcade at the equivalent of H648/Z150 depicting the distance McLain’s motorcycle would need to travel in 0.546 to 1.366 seconds to reach the Shot 1 acoustic zone.


In either case, in order to reach the acoustic zone in time, McLain would have to have accelerated his motorcycle to a speed significantly greater than it was mechanically capable of achieving.

In other words, there is direct photographic proof that less than 1.4 seconds before the first alleged shot, H.B. McLain, the only motorcycle escort in the entire motorcade who could possibly have been in a position to transmit the sound of gunshots, was 174 feet south of the required acoustic zone and therefore was incapable of being in the location necessary to validate the acoustics evidence.

And in case it’s not clear by now, the fact that McLain cannot reach the first shot location in the allotted time means he cannot make any of the other shot locations either, so all of the verbal gymnastics that Thomas marshals to present “negative evidence” that McLain is just out of sight of all the amateur cameras in Dealey Plaza as the remaining shots are fired is for naught.

Critical Reactions

There seems to be a general willingness to stick one’s head into the sand on this issue. Otherwise intelligent people want to pretend that my work on the photographic record as it relates to acoustics is either too hard to understand, doesn’t prove anything one way or the other, or doesn’t exist at all.

In 2003, Professor G. Robert Blakey, former chief counsel of the HSCA, told ABC News, “If you could prove to me that there was no police officer in the place where he had to be, you would falsify [the acoustics evidence].” [30]

This is, of course, in complete accord with the premise of the acoustics evidence and in keeping with what Dr. James Barger, lead scientist on the BBN acoustic study, wrote in 2001: “... if it can be shown that there was no vehicle or person with a police radio near the trajectory where I found it to be, then, that is impeaching evidence.” [31]

Three years after the Peter Jennings documentary aired on ABC television, and just before publishing the results of my study, I contacted Professor Blakey and offered to come to Notre Dame University (where Professor Blakey was teaching) at my expense and his convenience and show him why the photographic record is unimpeachable with regard to the question of whether any motorcycle actually exists at the location specified by the acoustics evidence. He declined to accept my offer.

Why? He stated that he would not understand it without having an expert present who understood what I did. I assured him even a five-year-old could understand my simple methodology and the abundant visual record. He still politely refused to look at the evidence. (Not that Professor Blakey is alone in this regard. When contacted by ABC News in 2003, Dr. James Barger, Mark Weiss and Ernest Aschkenasy also declined to look at the photographic record.)

Last August, I reiterated the offer to show Professor Blakey my work. He didn’t respond. Of course, Professor Blakey has no obligation to meet with me or review my work on this subject. Just the same, the offer stands.

Tightening the Truth

Last summer, a group of Internet based critics discovered an error I had made in calculating how one amateur film of the motorcade made by John Martin, Jr., synchronized with the Zapruder film. [32]

Their own diligence ultimately led them to conclude that the error was minor (I determined that the Martin film synchronization was off by 0.32 seconds) and did not affect the ultimate conclusion that no motorcycle was in a position to transmit the sounds of gunshots.

In the interest of accuracy, I spent the last few months re-examining the entire photographic record, correcting minor errors in the original report, and making adjustments where necessary.

The result is a revised and expanded report that strengthens the conclusion that the HSCA’s acoustic evidence of conspiracy is invalid.

It includes a new appendix documenting nine visual reference points common to the Hughes, Towner, Dorman, Bell, and Martin films and which confirm the synchronicity originally developed between the Hughes and Zapruder films. [See, Figure 16]



Figure 16. One of nine visual reference points confirming the synchronicity between the Hughes and Zapruder films. A man in a Stetson hat (No.1) can be seen in both the Towner and Bell films waving at the passing motorcade.


The newly revised report is available for download here.

The Scientist from Texas

One of the central themes of Hear No Evil is that over the last fifty years more than a few scientists and technical experts, whose work ultimately supported the thesis that Oswald acted alone, have tossed their ethics out the window and allowed political considerations to influence their judgment or have been co-opted by investigators with a political agenda. [33] In short, they’ve sold out and the public has been cheated out of an objective analysis of evidence in the Kennedy assassination.

But even a cursory reading of Mr. Thomas’ masterwork shows his own approach to the subject to be more ideological than objective, the same sin committed by many other conspiracy authors over the past five decades.

And despite noting that true scientists should “evaluate claims without respect to the social identity of those who make them,” [34] Mr. Thomas doesn’t mind heaping on the ad hominem attacks (referring to yours truly as “an uncredentialed amateur who was a long time critic of conspiracy theories”) when it suits him.

Of course, resorting to personal attacks reveals just how impoverished one’s position really is. And Mr. Thomas’ position is indeed bankrupt when it comes to the photographic record and acoustics.

Despite three opportunities in as many years to develop a coherent, factual refutation of my work and methodology, Thomas offers nothing more in Hear No Evil than a repetition of falsehoods, mischaracterizations, and outright lies that were long ago debunked.

As always, I am open to any new evidence that can help clarify the truth about the events of November 22, 1963.

I remain confident that the photographic record, as detailed in Epipolar Geometric Analysis of Amateur Films Related to Acoustics Evidence in the John F. Kennedy Assassination, establishes beyond all doubt that neither H.B. McLain nor any other motorcycle officer was in a position to transmit the sound of gunshots over the Dallas police radio system, as postulated by the 1979 House Select Committee on Assassinations, and consequently the acoustic evidence for conspiracy is invalid. [END]


Special thanks to Todd W. Vaughan for his contributions to this article.


Footnotes:


[1] HSCA Report, p.1

[2] Report of the Committee on Ballistic Acoustics, National Research Council, 1982, p.3

[3] HSCA Report, p.76

[4] Email group posting from James Barger, April, 2001

[5] ABC News, Peter Jennings Reporting: The Kennedy Assassination – Beyond Conspiracy, November 20, 2003

[6] Thomas, Donald Byron., Hear No Evil: Social Constructivism & The Forensic Evidence in the Kennedy Assassination, Mary Ferrell Foundation Press, 2010, Ipswich, MA, p.687

[7] Ibid, p.674

[8] Ibid, p.684

[9] Ibid, p.677

[10] Ibid, p.678

[11] Myers, Dale K., Epipolar Geometric Analysis of Amateur Films Related to Acoustics Evidence in the John F. Kennedy Assassination, Oak Cliff Press, 2007, p.123

[12] Ibid, p.65

[13] Ibid, p.66

[14] Thomas, Op. cit., pp.678-679

[15] Thomas, Op. cit., p.679

[16] Ibid

[17] Note: The program referred to, ABC News, Peter Jennings Reporting: The Kennedy Assassination – Beyond Conspiracy, first aired November 20, 2003.

[18] Thomas, Op. cit., p.676

[19] Thomas, Op. cit., p.590

[20] Thomas, Op. cit., pp.679-680

[21] Myers, Op. cit., p.42

[22] Ibid, pp.42 (fn 109), 43 (fn 111)

[23] Thomas, Op. cit., p.680

[24] 8HSCA22

[25] Thomas, Op. cit.

[26] 2HSCA59, 70, 71

[27] 8HSCA10, 28

[28] 8HSCA28 Note: BBN reported the WA motorcycle position as being 5 feet southwest of microphone position 3(4).

[29] Two additional matches for the second “shot” – one with a high correlation coefficient - indicated that the motorcycle not at 2(10) at the time of the second “shot,” but was at microphone position 2(6), located 36 feet east of 2(10).

[30] ABC News, Peter Jennings Reporting: The Kennedy Assassination – Beyond Conspiracy, 2003

[31] Email group posting from James Barger, April, 2001

[32] www.jfkassassinationforum.com, “JFK Film Alteration Revealed – Bombshell Dropped,” April 28, 2010 to June 18, 2010

[33] Thomas, Op. cit., pp.7-8

[34] Thomas, Op. cit., p.7

6 comments:

bvryder said...

Excellent piece, Dale - well done and many thanks.

As always, the devil is in the detail and I (for one) am entirely satisfied that your work on this issue still stands as 'the last word'.

There are plenty of other reasons to reject the notion a GK shot, of course, but with the above enhancement of your previous study, I think that it really is time for Professor Blakeley, and maybe Mr. Thomas, too, to give you a call.

Many thanks again for your invaluable contribution to the historical record.

Barry
London

David Von Pein said...

This is yet another excellent and very detailed article penned by Dale K. Myers. I thoroughly enjoyed reading it.

The demonstrable PROOF that completely demolishes the HSCA's paper-thin "4th shot" conclusion has been available to read on Mr. Myers' website for years.

And this new 2010 article in response to Don Thomas' recent book only further enhances and supports the ironclad proof that no motorcycle was in a position where it needed to be to support the HSCA's acoustical findings of a fourth gunshot.

Why conspiracy theorists continue to cling to this acoustical nonsense is a bigger mystery to me than Bigfoot.

And, of course, Dale could have added still more insult to Don Thomas' injury if he had chosen to do so, because Mr. Myers' 11/19/2010 article doesn't even touch upon the OTHER major reason to know that the acoustical/Dictabelt evidence is invalid -- that being the very high likelihood (thanks to Steve Barber's 1979 discovery) that the "impulse" sounds that the HSCA said were "gunshots" on the Dallas Police Dictabelt are actually occurring about a full minute AFTER the assassination had taken place in Dallas' Dealey Plaza.

So there are multiple reasons to be skeptical of the HSCA's acoustical analysis, and yet people like Donald Thomas seem totally oblivious to any of the various problems that exist with the acoustics evidence.

But, as Dale Myers himself said (when talking about another conspiracy theorist, Oliver Stone, and the same quote is certainly applicable here when discussing Donald Thomas' stubbornness regarding the acoustical evidence):

"Apparently, reality doesn’t set well with the Hollywood filmmaker [Oliver Stone]. Denial is SO much more comforting." -- Dale K. Myers; January 25, 2010

Paul C. said...

You're to be commended for strictly limiting the discussion in your articles to your own unique contribution to the topic - the detailed photographic analysis, correlation, and computer model. But it must also be said that the HSCA acoustical evidence and conclusions have been utterly discounted by multiple lines of evidence, totally unrelated to the photographs and films. It is incomprehensible that anyone would still try to find validity in them at this point. Please continue to be an aggressive voice of reason and rationality.

Anonymous said...

In viewing Mr. Myers materials/reconstruction of the assassination I see one VERY important detail that will need to be addressed.

May I ask, at the moment JFK emerges from behind the Stemmons Freeway, sign we can all agree that his hands, both his left and right, are almost even with his neck and throat? We see his (JFK's) cuffs. Correct? Well, IF Mr. Myers assumption of the bullet puffing out Gov. Connelly's jacket lapel (and he did have a hole in it) occurs a few frames later (and this is what he is stating as a thesis) then how can Kennedy have moved his hands (which were: Left hand on lap, Right hand on door frame) faster than the time the bullet actually would take to fly into and out of Connolly, let alone cause the flap of his Jacket Lapel??

There is simply no way that Kennedy could have been hit in the back and have gotten his hands up to his throat BEFORE we see that puffing Jacket. Kennedy was not faster than a speeding bullet ( which I'll assume was traveling at 1100-1300 fps). I'd like some thoughts on this. We can clearly see JFK responding to his wounds BEFORE the bullet flap. People just don't move that fast.

Dale K. Myers said...

Good question regarding JFK's hand's at the moment of impact. What you've missed is that Kennedy's hands are already in front of his chest as he emerges from behind the Stemmons Freeway sign - coming together in a hand-clasp - as seen earlier in the motorcade. The president is continually seen clasping (and unclasping) his right and left hands before and after waving at the crowd and/or brushing his hair back. In the last few seconds of his life (as the car turned the corner onto Elm) this occurs five times - the last just as he disappears from view behind the Stemmons sign. As he re-emerges, his hands are in the process of re-clasping just as he is hit. The bullet would have passed between his hands as it emerged out of his throat. This can be seen in the 3D reconstruction that I did. So, in fact, the president doesn't bring his hands up to his throat before Connally's coat flap, his hands are already in front of his chest in the process of re-clasping (as he had done many times before) just as the bullet struck.

HIDEJI OKINA said...

I’m Japaneseassassination researcher.
Today I buy a Mr.THOMAS's book.
I wondered he believed a "Grassy Knoll Shooter".
He write "The bullet entered the President's right temple just at the hearline.It exited at the posterior arc of the right parietal bone"(p.715).
Knoll shooter bullet turn to the right after the hit?
This book is waste of time and money.
I enjoy read your book "WITH MALICE" new version.
Best regards.