Monday, April 7, 2008

Photographic Proof: H.B. McLain and Acoustics

by DALE K. MYERS

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After nine months, entomologist and part-time conspiracy theorist Donald B. Thomas has finally weighed in on my 2007 research paper, “Epipolar Geometric Analysis of Amateur Films Related to Acoustics Evidence in the John F. Kennedy Assassination.”

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 in 1979.

Mr. Thomas’ meandering, contradictory, and sadly laughable critique, “The Bike with the Mike,” dated March 3, 2008, and posted on the Mary Ferrell Foundation website, fails to offer anything that could remotely be considered a challenge to that conclusion.

Mr. Thomas, whose Science & Justice article “Echo correlation analysis and acoustic evidence in the Kennedy assassination revisited” grabbed headlines in 2001, promises his readers that he “will show that the study by Myers contains serious errors that invalidate his conclusions.” According to Thomas, those errors include (among others):

(1) “… [Myers] mis-synchronizes the acoustical evidence by placing the shooting one second earlier than it was.”

(2) “… [Myers] misplaces the vehicles as seen in the Hughes film because he misplaced the position of Mr. Hughes.”

(3) “… [Myers then] compounded the error in placement by over-estimating the speed of the vehicles. Thus, in his reconstruction the vehicles are further north and traveling faster than they really were.”

(4) “… [Myers’ reconstruction] includes an untestable assumption concerning the movement of the procession. Myers assumes a steady even pace, contrary to the memories of the police officers in the escort who recall a stop and go movement.”

According to Thomas, the combination of these errors “…results in a time line which is about 3-1/2 seconds shorter than it would be without the errors. Removing those errors leaves McLain with approximately 4 seconds to cover the 174 ft (requiring a speed of about 25 mph)…” to reach the location necessary for the HSCA’s acoustic evidence to be valid.

Each and every one of Thomas’ allegations (including the four mentioned above) is false. So too are his conclusions, as you’ll soon see.

None of this is a surprise to me. I examined and laid bare the contradictions in Mr. Thomas’ own acoustic hypothesis as it relates to the photographic record in my 2007 research paper. In his critique of that report, Thomas offers nothing that remotely could be considered a challenge to my appraisal of his hypothesis. In fact, his critique is yet another rather embarrassing exposé of the faults and contradictions in his own hypothesis.

Those who have already read my 2007 paper on this issue (and I encourage those who haven’t read it to do so before proceeding with this essay) know that the photographic evidence shows that H.B. McLain, the motorcade officer suspected by the HSCA of having the open microphone, was 174.38 feet from the position predicted by the acoustic evidence just 0.546 seconds before the suspected first shot. In order for the acoustic evidence to be valid, McLain would had to have accelerated to a speed significantly greater than 198 mph on a Harley-Davidson motorcycle which was only capable of a top speed of 95 mph. Obviously, this would be impossible.

Thus, the HSCA’s acoustic evidence is rendered invalid since neither McLain nor any other motorcycle officer could have been in a position to transmit the sounds of gunshots over the Dallas police radio system.

In order to resurrect the HSCA’s acoustic evidence photographically, conspiracy theorists need to buy McLain more time to get to that first microphone position, so it’s no real surprise that Mr. Thomas’ critique attempts to do just that. However, he fails in this effort, miserably.

The Low Road

Before diving into the heart of his critique, Thomas takes the low road and attempts to discredit my past work on the assassination case. First, he belittles the 2003 ABC News special in which I participated, writing:

“…The ABC documentary claimed that a computerized reconstruction based on the ‘Leon Zapruder film,’ which it described as ‘the only film of the president’s murder,’ proved that there was no motorcycle at the specified locations during the shooting.”

Of course, any assassination student knows that it was Abraham Zapruder’s film (not Leon Zapruder) that my computer reconstruction was based on, and that the Zapruder film was not the only film of the president’s murder. And any student of the assassination also knows that the ABC News program never made such a statement, and that Thomas lifted the erroneous language from the text printed on the back cover of Koch Vision’s DVD release of the program (“…computer animator Dale Myers created a digital simulation of the only known film of the murder, a 16 mm home movie taken by Leon Zapruder…”), which ABC News had nothing to do with.

The fact that Mr. Thomas even takes the time to harp on such an obvious editorial error speaks volumes about how little he really has to offer in the way of criticism regarding my work on photographic issues related to acoustics in the Kennedy assassination.

Mr. Thomas continues his trek down the low road warning his readers:

“…the essay by Myers contains a personal attack on the author of this critique for his support of the acoustical evidence…”

This is a reference to “Appendix IV – Critique of Donald B. Thomas’ Analysis of Photographic Evidence Related to the Acoustic Evidence,” which appears at the end of my 2007 paper. In introducing that section, I wrote, “Since the photographic record proves that the acoustic evidence utilized by Thomas and the HSCA to support a conspiracy is invalid, the following section focuses on additional errors and omissions in Thomas’ photographic analysis which he offered in support of the acoustic evidence, and hence, a conspiracy in the assassination of President Kennedy.”

Appendix IV is not a personal attack on Mr. Thomas. It is a critique of his many written statements and claims made in defense of the acoustic evidence as it relates to the photographic record. And since Mr. Thomas is considered in some circles to be one of the leading authorities on the acoustic issue, it was incumbent upon me to address those claims which relate directly to photographic issues discussed in my 2007 report.

As it is, I found many of Mr. Thomas’ claims to be factoids with little or no basis in fact and I presented evidence and citations to support my arguments in a clear and professional manner. I invite you to read that section and judge for yourself.

Thomas also warns the readers of his critique:

“…Myers is the author of a previous book on the Kennedy assassination which argued against conspiracy theories.”

This is a reference to my 1998 book, With Malice: Lee Harvey Oswald and the Murder of Officer J.D. Tippit, which offered a second-by-second account of that murder, the aftermath, and a detailed analysis of the evidence both for and against conspiracy in the Tippit murder – not an indictment against conspiracy theories in general, as Thomas suggests.

I suppose I could take Mr. Thomas’ not-so-veiled suggestion that I am biased in my views on the Kennedy assassination, and therefore somehow untrustworthy, as a personal attack. I don’t. I recognize Thomas’ comments for what they are – an ad hominem argument (i.e., one designed to poison the well, so to speak, and convince readers in advance to question me as a source), which generally is only used by those whose position is so weak that they must revert to attacking the person making an argument rather than countering that argument with facts.

In another ad hominem effort, Mr. Thomas warns readers about the “risk” of reading my 2007 report and attempts to explain why it took him the better part of nine months to point out the deficiencies in a research paper he obviously considers transparently thin, writing:

“…I have delayed responding to Myers in the hopes that someone more disinterested would point out the problems with his analysis, but so far only one person has done so, and on procedural rather than evidentiary grounds, and this anonymously to a discussion group which included myself and Myers. I find that Myers’ characterizations of the evidence in general and of my views in particular are actually caricatures; i.e., straw man arguments. Suffice it to say that anyone relying on Myers’ version of the evidence, and my analysis, does so at their own risk.”

I suspect there is only one reason Mr. Thomas is afraid you might read my 2007 report – it destroys his credibility. Why not judge for yourself? I invite you to read my 2007 report, and I encourage you to read the various reports and presentations Mr. Thomas has offered over the last few years. Check the sources I provide, and his. Ask yourself, who has more credibility on this subject and who is afraid of the truth?

Two quick points about the anonymous person who, according to Thomas, pointed out procedural rather than evidentiary problems with my work:

First, and foremost, I don’t respond to anonymous postings. If you can’t put your name on it, it’s not worth my time.

Second, the poster referred to by Thomas complained that my 2007 report didn’t contain a frame-by-frame map of the positions of each and every car and motorcycle in the motorcade (apparently 100 graphic exhibits weren’t enough), failed to present a scale in any of the graphics (in fact, distances and dimensions are presented in all graphics of consequence), and inadequately identified McLain in the Hughes film (actually, McLain identified himself in the Hughes film). The anonymous post was roundly ignored at the time, and deservedly so, by the thirty-plus members of the private email chain.

As for Thomas’ “straw man” claims, I prefer to let my work speak for itself and let the chips fall where they may. I’ve done the work. The facts and the evidence are there. You be the judge.

Here now are some of the charges Thomas makes in his recent critique and the truth of the matter.

Garbage In, Garbage Out

“…a major problem with the computer study is that Myers fails to provide the reader with the information that was put into the computer. This makes it quite difficult for a critical reviewer to judge the validity of the conclusions of the study; meaning that if it was garbage in, then it will be garbage out…”

The 179-page graphical report I produced in 2007 details the creation of the models used in the computer reconstruction (including the sources of those models), how the positions of each photographer was determined, how geometric relationships were established by comparing the photographic record with lines-of-sight, and how those relationships established a single, continuous timeline which revealed the precise speed, path and position of each of the pertinent motorcade vehicles at the time the assassination shots were fired, including Officer H.B. McLain’s motorcycle.

What is it that Mr. Thomas, and others who make this same argument, expect me to provide beyond that which I have already provided? Do they expect me to offer the Cartesian coordinates of each vertex of every computer model at every frame of the analysis before they’ll consider accepting the results? Perhaps they would prefer to sit alongside me through the thousands of hours it took to actually perform the tasks necessary to achieve accurate results?

The ‘garbage in, garbage out’ argument amounts to nothing more than a new spin on the ad hominem argument – one that can be leveled against anyone using technology as a tool without offering any substantial evidence to support the charge. The ‘garbage in, garbage out’ argument is designed to conjure up images of some mystical, magical, and unknowable process that is being orchestrated by some supernatural wizard deluxe who intends to fool the public with technology. In short, “Pay no attention to the man behind the curtain!”

I have provided more than enough information to duplicate what I did using a variety of methods – technologically based, or otherwise. It is not rocket science. Those who claim that I didn’t provide enough information about my methodology either don’t understand the simplicity of it or are too lazy to duplicate it.

Epipolar Geometry

“…One measure of the reliability of Myers' analysis is his use of the term ‘Epipolar Geometric’ in the title…”

Here, Thomas attempts to undermine my analysis by claiming that the term ‘epipolar geometry,’ which describes the geometric relationship between two optical systems viewing the same subject and which can be used to locate points or objects in space, has little or nothing to do with my methodology.

After explaining the term ‘epipolar geometry’ using language and graphics borrowed from but not credited to Wikipedia’s website, Thomas writes:

“…The problem is that the key analysis used by Myers involves images taken by Abraham Zapruder and by Robert Hughes. At no time does Zapruder appear in any of the Hughes frames nor at any time does Hughes appear in Zapruder’s film. Hence, there are no epipoles or epipolar lines or epipolar geometry involved in Myers' key analysis, or any other analysis as far as I can tell. Rather, Myers uses line of sight to estimate the positions of the cars in the motorcade, but without the exactitude implied by the use of ‘epipolar geometry’.”

Here’s what I wrote on page 42 of the 2007 report regarding the use of triangulation in pinpointing the location of objects in space, “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]

Two 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]

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, based on a very narrow reading of Wikipedia’s definition of the term ‘epipolar geometry’ or the application(s) of this mathematical science, is false and misleading.

The Acoustic Evidence

“… [Myers] does not provide an accurate presentation of the acoustics, and certainly does not correctly relate my analysis of the acoustical evidence. This is critical because in order for the filmed evidence to constitute a fair test of the acoustical evidence the latter has to be posited correctly and Myers fails to do so…”

Here’s what I wrote on page 148 of the 2007 report regarding the order and timing of the shots as presented by the HSCA and Mr. Thomas: “…While the acoustic experts hired by the HSCA determined that the Dallas police audio recording contained evidence of four gunshots, Thomas proposed that the Dallas police recording actually contains evidence of five shots. Thomas also claimed that the timing of the shots was different than the timing proposed by the HSCA. And most important of all, Thomas believed the fatal head shot was fired from the grassy knoll, not the Texas School Book Depository as the HSCA concluded. A necessary consequence of Thomas’ belief that the fatal head shot was fired from the grassy knoll is a re-ordered shot sequence that begins later than the sequence proposed by the HSCA…”

Not only is the above summary accurate, it is supported by Thomas’ own writings as well as the conclusions of the HSCA.

Mr. Thomas complains that I failed to report both the correct number of total acoustic impulses (identified by the HSCA as shots) and the HSCA’s synchronization of the first acoustic impulse, writing:

“…Myers specifically contends that the HSCA’s acoustical experts found four suspect sounds on the police tapes to match with their test shots (I report five) and that the first synchronizes to Zapruder frame 160 (as opposed to my synchronization of the first shot with Z-175). But Myers’ contention is wrong on both counts…”

The acoustic experts at Bolt, Beranek and Newman (BBN) examined a number of potential matches between the 1963 Dallas police recording and their 1978 test firings. They eliminated all but four sound impulses because some of those impulses were deemed “false alarms” for a variety of reasons (i.e., some failed to score higher than the minimum coefficient threshold of 0.6, some could only have happened under impossible circumstances, etc.).

In the end, the HSCA acoustic experts found (i.e., they concluded) that there were four sound impulses that might be gunshots. [1] Synchronizing the last of the four impulses with the fatal head shot demonstrates that the first suspected gunshot was fired at the equivalent of Z160. [2]

All of this is a matter of record, notwithstanding Mr. Thomas’ reinstatement of one of the sound impulses BBN rejected as a false alarm and his re-synchronization of those sound impulses (now totaling five).

In order to perpetuate the myth that BBN actually concluded that five sound impulses were on the Dallas police recording and not just four as I reported, Thomas writes:

“…Referring to [Table II] one finds that five of the patterns have a score of 0.6 or higher, these being the ones designated at: 137.70, 139.27, 140.32, 145.15 and 145.61 sec. That is five, not four; matching sound patterns were found and reported by the HSCA acoustical experts…”

Yes, BBN found five sound impulse patterns that had a coefficient score of 0.6 or higher (meaning these sound patterns were statistically significant), but they didn’t conclude that there were five total impulse sounds suspected of being gunshots. Why? Because they eliminated one of the five impulse patterns they initially reported. But Mr. Thomas doesn’t say that, does he?

The sound impulse that was eliminated – the one fired from the Texas School Book Depository at 140.32 seconds – was deemed to be a “false alarm” (i.e., a false positive) because “it occurred only 1.05 [seconds] later than the [three] earlier correlations also obtained from the [Texas School Book Depository]. The [Mannlicher-Carcano] rifle cannot be fired that rapidly. Since there are three correlations plausibly indicating the earlier shot, the one occurring 1.05 seconds later must be a false alarm.” [3]

In other words, BBN found three correlations matching the sixth floor window of the Texas School Book Depository at 139.27 seconds and only one match at 140.32 seconds. Since Oswald’s Mannlicher-Carcano rifle couldn’t be fired twice during that 1.05 second span, the weight of the acoustic evidence favored the 139.27 second match as being genuine and the 140.32 second match as false.

“…When these [time] corrections are applied to the times in Table II the four time intervals among the five putative gunshots are 1.65, 1.1, 4.8 and 0.7 sec. Consequently, the time of the first acoustically identified shot synchronizes to Z-frame 175, not 160 as claimed by Myers. The math is simple, (4.8+1.1+1.65 = 7.55 sec), (7.55 sec x 18.3 fps = 138 Z-frames), and because the fourth putative shot came from the grassy knoll and the fatal shot is at Z-313, thus, 313-138 = frame 175. These intervals come directly from the BBN report…”

Yes, the intervals do come directly from the BBN report, but Mr. Thomas’ synchronization does not, does it?

Look at the math in Mr. Thomas’ example above. He lists the four time intervals among the five putative gunshots as 1.65, 1.1, 4.8 and 0.7 seconds. But when he adds up the time intervals to determine the moment of the first shot he doesn’t use the last listed interval of 0.7 seconds. Why? Because, Mr. Thomas declares, “the fourth putative shot came from the grassy knoll,” [emphasis added] and that this fourth shot equates to the fatal head shot.

Mr. Thomas’ declaration that a grassy knoll shot blew Kennedy’s head off is not a scientific fact born out of BBN’s analysis of the acoustic evidence. It has nothing whatsoever to do with the acoustic evidence. It has everything to do with Mr. Thomas’ own personal belief that Kennedy was killed by gunfire originating from the grassy knoll.

Yet, there is not one scrap of scientific evidence to support this. In fact, seventeen forensic pathologists, including the HSCA Pathology Panel, have concluded that there is no physical, scientific, forensic evidence that President Kennedy was struck in the head by a shot fired from the grassy knoll. The president received one fatal wound in the head as evidenced by an entry wound in the back of the head caused by a bullet fired from above and behind. That scientific fact led the HSCA to conclude that even if a bullet had been fired from the grassy knoll (as their acoustic evidence indicated) it could not have struck the president.

Mr. Thomas, on the other hand, completely rejects the findings of these experts and concludes that Kennedy was indeed hit from the grassy knoll.

So, in fact, it is not BBN’s acoustic data that Mr. Thomas bases his re-synchronization upon, but rather his own unsupported and unqualified opinion that Kennedy was hit in the head with a bullet fired from the grassy knoll – a bullet that left no scientific trace.

And so, working the numbers a couple of different ways, Mr. Thomas concludes that the first shot was fired at the equivalent of Zapruder frame Z175, assuming of course that BBN’s grassy knoll shot is synchronized with the fatal head shot at Z313. Mr. Thomas writes,

“…The values reported in my essays and lectures come directly from the data in the BBN report and thus are entirely in accord with the HSCA acoustical evidence. The discrepancy is not between my analysis and the acoustical evidence, but between the acoustical evidence and the way it was subsequently manipulated using non-acoustical evidence.”

But, of course! Mr. Thomas’ interpretation of the acoustic evidence is not to blame. It is the evil-doers at the HSCA who manipulated the purity of the BBN data using “non-acoustical evidence” – i.e., the expertise of seventeen forensic pathologists who based their conclusions on the authenticated photographs and X-rays taken at Kennedy’s autopsy.

The only manipulation going on here is the manipulation of information presented by Mr. Thomas.

All of Thomas’ shenanigans with the total number of acoustic impulses, the intervals between those impulses, [4] and his efforts to re-synchronize the shot sequence regardless of photographic and scientific evidence to the contrary were reported at length in my 2007 paper. (See Appendix IV)

In particular, I addressed the very issue that Thomas argues now – that placing the first shot at Z175 (instead of Z160) allows H.B. McLain enough time to reach BBN’s first shot location thereby validating the acoustic evidence. The results I reported in 2007 show that McLain could not get to the first shot location in the time allotted even if the first shot were fired as late as Z175. [5]

It’s no surprise to me that you won’t find one word about those results in Mr. Thomas’ critique. And no doubt you’ve surmised by now that this is one of the chief reasons that Mr. Thomas doesn’t want you to read my 2007 report.

The Mannlicher-Carcano Rifle

“…The acoustical experts were told falsely that the murder weapon could be cycled in 1.6 sec, an error repeated by Myers…”

The HSCA test fired a Mannlicher-Carcano rifle using the open iron sights rather than the rifle’s scope and found that it was possible for two shots to be fired within 1.66 seconds. [6] This fact was properly noted by me on page 152 of my 2007 report. Mr. Thomas, who chooses to characterize this fact as “false,” offers no facts of his own to support his opinion.

All of this is minutia anyway since the question of whether Oswald could fire two shots within 1.66 seconds is only applicable if one accepts the acoustic evidence as valid – the very issue in question. Indeed, my work on the photographic evidence demonstrates that the acoustic evidence is invalid.

Reinstating a Fifth Shot

“…This erroneous, non-acoustical evidence, along with some tortured logic, led the HSCA to discard one of the acoustical matches as a false positive. This changed the number of shots from five to four, but this does not affect the timing of the first shot. In my analysis I reinstated the matching evidence because the grounds for declaring the match at 140.3 sec as a false positive were invalid…”

Mr. Thomas’ unsupported opinion aside, reinstating BBN’s discarded 140.32 sound impulse and calling it a shot raises several insurmountable problems that Thomas never addresses.

Resurrecting the BBN sound impulse at 140.32 (which matched a test shot fired from the Texas School Book Depository’s sixth floor southeast corner window) means that three shots would have been fired from the Depository’s sniper’s nest in the span of 2.62 seconds – with a interval of 1.57 seconds between the first and second shots, and 1.05 seconds between the second and third shots.

This creates a huge (and dare I say, impossible) timing problem – three shots fired from Oswald’s bolt-action Mannlicher-Carcano rifle in less than three seconds!

How does Mr. Thomas get around this problem? Simple, he declares the sound impulse at 139.27 (the second in the sequence of three, and one that BBN identified as having been fired from the sixth floor sniper’s nest window) as being a “rogue” shot fired by a second gunman located somewhere to the rear of the president’s limousine.

Where did the so-called “rogue” shot go, and who fired it? Mr. Thomas doesn’t seem to know, telling an interviewer in 2006, “We really don’t know where it went. We don’t know where it came from.” [7]

Huh? Let’s make this real clear: To overcome timing problems stemming from his resurrection of BBN’s rejected impulse sound at 140.32, Thomas declares that the impulse sound at 139.27 was not fired from the sixth floor sniper’s nest window but was fired instead from some other unknown location to the rear of the president’s limousine – somewhere other than where the BBN test data indicated.

Does Thomas really believe that the BBN test firing from the Texas School Book Depository’s 6th floor southeast corner window is somehow equivalent to a test firing from some other location? Because if he does, he is rejecting the very methodology upon which BBN’s entire acoustic evidence is based.

If there is one thing that is absolutely clear, it is that the BBN test results depend on the belief that each individual firing location and each individual recording location create unique, echo patterns.

Mr. Thomas obviously doesn’t understand this basic fundamental concept. In a recent email exchange, Thomas offered this, “…the procedure applied by BBN does not limit the origin of the shots to two and only two locations. The data in their Table II was the result of an experiment which was designed to locate the open microphone, not pinpoint the origin of the shots. Lead scientist James Barger explained in testimony that his array of microphones was ‘a net to capture a motorcycle.’ Test shots were only fired from two locations and hence, the suspect sounds could only have matched to one (or both) of the two locations, regardless of where they may have originated.” [8]

Yet, Thomas couldn’t be more wrong!

Dr. James Barger testified on this very issue telling counsel for the committee Jim Wolf, “There is a pattern of sounds that emanate from each microphone when each rifle is fired that is unique and that pattern is a much a fingerprint that identifies two things uniquely, the location of the rifle and the location of the receiver.” [emphasis added] [9]

Again, this same basic concept appears in numerous locations throughout the HSCA’s report. For instance, in Section 5 of BBN’s report, we find this, “The objective of the acoustical reconstruction, therefore, was to obtain several ‘acoustical fingerprints’ of the sound of gunfire in Dealey Plaza to compare with the impulse patterns found on the Channel l tape. If any of the ‘fingerprints’ matched, then the reconstruction would result in determining both the timing of the shots and the locations of the weapon…” [emphasis added] [10]

And again, in Weiss and Aschkenasy’s report, we find this, “…assuming a fixed location of a listener, the echoes that he hears and the times at which he hears them will be related uniquely to the location of the gun, since for each different location of the gun, even though the distances from the listener to the various echo-producing objects are the same the distances from these objects to each gun location are different. Consequently, the times at which the echoes are heard will be different for each location of the gun… Because the echo travel times are uniquely related to the locations of the gun and the listener, the echo-delay times are unique to any given pair of those locations.” [emphasis added] [11]

By resurrecting and declaring the impulse sound at 140.32 a “rogue” shot fired from a location other than the sniper’s nest window, Thomas is calling into question both the methodology and the conclusions of BBN’s test firings. In essence, he’s making up his own methodology and results, telling us that BBN was wrong; that they made a mistake and that any test firing results can be manipulated to suit any situation.

What in the world is Thomas doing here? If one shot location can be moved at will, why not move all of the shots to different locations? Why not have gunmen shooting from trees, and sewer openings, and overpasses? Can it get any sillier?

I’m afraid it can. By reshuffling the shot sequence and re-synchronizing BBN’s grassy knoll shot to the fatal head shot, Mr. Thomas is forced to conclude that the first sound impulse synchronizes to Zapruder frame Z175. This creates another timing problem, one that involves the reactions of Governor John B. Connally and Mrs. Jacqueline B. Kennedy.

According to Connally’s testimony, he heard a high-powered rifle shot and turned to his right. Connally’s reaction can be seen in the Zapruder film beginning at Z162. Mrs. Kennedy testified that she heard what she thought was a backfire, then heard Governor Connally yelling and turned to her right, which we also see beginning at Z167.

If the first shot wasn’t fired until Z175, as Mr. Thomas claims, what “shot” are Governor Connally and Mrs. Kennedy responding to at Z162-167?

Mr. Thomas claims to solve this problem by declaring that an inexplicable “noise” occurred at the equivalent of Zapruder frame Z147 and that this caused Governor Connally’s reaction. [12] We’re supposed to accept this dubious explanation even though Thomas fails to determine what this “noise” was or where it came from; or even acknowledge that Governor Connally, an avid hunter, immediately recognized the sound as a high-powered rifle shot, not some inexplicable noise.

Why did Thomas select Zapruder frame Z147 and not some other frame for the moment of the “noise,” you ask? Mr. Thomas tells us that the timing fits yet another impulse sound pattern discarded by BBN – one noted as occurring at the 136.20 second mark, [13] some 1.5 seconds before the sound impulse matching Thomas’ first shot (Z175).

That discarded sound impulse would have occurred at the equivalent of Zapruder frame Z147, assuming of course that we accept Thomas’ synchronization of the grassy knoll shot to the fatal head shot. [14]

Why does Mr. Thomas claim that the impulse sound heard at Z147 was a “noise” and not a gunshot? No doubt it is because BBN never provided the matching data for the impulse sound they eliminated on grounds it was below the coefficient threshold of 0.6 – the minimum value for accepting a match.

All of this leaves Mr. Thomas grasping for straws and inventing ridiculous theories to explain Governor Connally and Mrs. Kennedy’s reactions, as seen at Zapruder frames Z162-167.

Synchronizing the Acoustic Impulses

In an effort to explain how the HSCA managed to improperly synchronize the acoustic impulses with the Zapruder film, Mr. Thomas writes,

“…More importantly for this discussion, when the acoustical experts were asked to collaborate with an expert on the Zapruder film (Robert Groden) to attempt a synchronization of the acoustical evidence with the video evidence, they were told that any gunshot from the grassy knoll must have missed. But because the acoustical experts were not persuaded by that contention, perhaps aware that the forensic pathology panel had actually split on this issue, they produced two synchronizations (8 HSCA 107-108): one in which the fatal shot was set to a book depository shot, and one where the fatal shot was set to the grassy knoll shot…”

Two synchronizations were prepared by the acoustic experts because they assumed that either the third of fourth shot struck the president’s head (as Thomas’ own citation – 8HSCA107-108 – shows), not because they were told that the grassy knoll shot missed, or that they weren’t persuaded by the evidence that the grassy knoll shot had missed, or even because the forensic panel had “split” on the issue – as Thomas contends. In fact, the forensic panel was not split on the issue of whether the grassy knoll shot had missed.

The majority of the nine-member forensic pathology panel concluded that Kennedy was struck from behind by only two bullets and that the damage to the president’s head was caused by only one bullet fired from behind. [15] Only one member dissented from this finding – Dr. Cyril H. Wecht, the longtime conspiracy advocate who argued that Kennedy could have been struck from the grassy knoll by “some type of relatively frangible ammunition.” [16]

Despite a lengthy, detailed report on the reasons for his dissention, Dr. Wecht failed to change the minds of any of the other eight members of the HSCA forensic panel. [17]

This was the same Dr. Wecht who testified before the Rockefeller Commission four years earlier that the evidence established that there was only one head shot and it was fired from behind. [18] As I pointed out earlier, seventeen pathologists have reviewed the autopsy materials and agree that there is only one entrance wound in the president’s skull – in the back of the head.

In order to reconcile the acoustic evidence with the filmed record, the HSCA prepared two possible synchronizations: One assumed the fourth acoustic shot (fired from the Book Depository) caused the fatal head shot, the other assumed the third acoustic shot (fired from the grassy knoll) caused the fatal head shot. [19]

Not only did the synchronization of the fourth acoustic shot (fired from the Depository) and the fatal head shot tie together all of the scientific evidence in a believable way, but the alignment of the third acoustic shot (fired from the grassy knoll) with the fatal head shot produced a major gap in the evidence – no shot fired from the Book Depository would have struck the President in the head at any time – a finding completely contrary to the weight of scientific evidence. [20]

Mr. Thomas’ own theory contains the same fatal flaw – none of the five shots he proposes struck the back of Kennedy’s head – a claim that is, frankly, preposterous in the face of irrefutable scientific evidence to the contrary. [21]

The Mayor’s Car

Mr. Thomas focuses considerable energy in his critique on what he calls “negative evidence” – the lack of photographic evidence showing McLain at the time and location predicted by the acoustics evidence. According to Thomas, McLain should be near the motorcade vehicle occupied by Mayor Earle Cabell at the time of the first shot. Mr. Thomas writes:

“…The motorcade vehicle in the immediate vicinity of the predicted location was the mayor’s car… Frustratingly, of the first nine cars in the motorcade the only one which is never visible in the Zapruder film happens to be the mayor’s car. But because of Myers’ faulty analysis this significant fact never surfaces…”

Anyone reading my 2007 report on this issue knows there is no faulty analysis and no significant fact overlooked, as Thomas falsely charges.

First, contrary to Thomas’ claim, the mayor’s car – a white 1963 Mercury Comet convertible – is visible in the Zapruder film, appearing between Zapruder frames Z178 and Z196.

In 1982, Gary Mack reported a moving object in the Zapruder film that he thought might be H.B. McLain’s motorcycle at the exact time and location predicted by the HSCA acoustic analysis.

Second, stabilization techniques I performed on the region of the Zapruder film in question showed that the object thought to be McLain was actually the 1963 Mercury Comet convertible carrying Dallas Mayor Earle Cabell and his party. (See: Figure 1) And because the windshield of the Dallas mayor’s car is distinguishable in several of the frames, it was possible to accurately determine the position and speed of the vehicle in relation to the rest of the motorcade.

All of these facts were detailed on page 22 of my 2007 report.



Figure 1. Stabilized Zapruder film sequence – Z170-208


A Motorcycle on Houston Street

Another example of “negative evidence” cited by Thomas relates to McLain’s journey north on Houston Street. Mr. Thomas writes:

“…Between Z-frames 200 and 250, Zapruder panned his camera to the right providing a glimpse of the motorcade on Houston Street including views of the 7th, 8th, and 9th cars. Many researchers have searched these frames for any indication of the motorcycle and none has been found…”

While it is true that McLain’s motorcycle is not seen traveling north on Houston Street during the Zapruder film sequence Z200-Z250; Mr. Thomas’ suggestion that this somehow supports his thesis that McLain is at the Elm and Houston intersection transmitting the sounds of gunshots is false.

The fact that McLain does not appear during the sequence doesn’t mean anything – remember Thomas believes that McLain is far ahead of the area visible between Zapruder frames Z200-250 and my own analysis of the photographic record indicates that McLain had yet to enter the area in question. So in fact, neither of us expects to see McLain in that portion of the Zapruder film.

What is particularly important (and a fact that Thomas fails to mention at all in his critique) is that I discovered Marion L. Baker’s motorcycle, McLain’s partner, moving north on Houston Street between Zapruder frames Z241 and Z255. [22]

This is extremely significant, because Baker’s position during this sequence independently synchronizes the Hughes and Zapruder films at H648/Z150, proving that McLain had just 0.546 seconds (assuming the first shot was fired at Z160) or just 1.37 seconds (assuming as Thomas does that the first shot was fired at Z175) to traverse 174.38 feet. In either case, it would be physically impossible for McLain to accomplish this task, a central fact of my work and one that Thomas completely ignores. [23]

Locating McLain’s Motorcycle

The best that Mr. Thomas and others intent on keeping the HSCA’s acoustics evidence alive can hope for is that the photographic record is ambiguous when it comes to McLain’s position at the time of the shooting. In his critique, Mr. Thomas suggests that the “negative evidence” of McLain’s exact position and its implications was not made clear in my 2007 report, writing:

“…This negative evidence means that at the time of the shooting, McLain’s motorcycle was either in exactly the right place predicted by the acoustical evidence … or much further back … the latter being Myers’ conclusion. This dichotomy, and its implications, was not made clear by Myers…”

This is nonsense, of course. The central purpose of my photographic work was to determine the location of McLain at the time of the acoustic impulses. My search for evidence of McLain’s motorcycle moving north along Houston Street during Zapruder frames Z200-Z255, my subsequent discovery of escort partner Marion L. Baker’s motorcycle during this sequence, and my work to establish the synchronicity of the Zapruder and Hughes films based on Baker’s movements were all efforts made to achieve the goal of locating McLain.

The discovery of Baker’s motorcycle, which by all photographic and testimonial accounts was ahead of McLain’s position as they moved north on Houston Street, helps in that effort by lending credence to the belief that McLain was still behind and to the left of Baker and consequently had not yet entered Zapruder’s field of view by frame Z255.

The synchronization of the Zapruder and Hughes films, using Baker’s movements – independent of all other synchronizations – confirms this belief by demonstrating that McLain could not have traversed the required 174.38 foot distance before the first shot was fired – either at Z160 (according to the HSCA) or Z175 (according to Thomas).

Mr. Thomas seems to want to ignore all of this and focus instead on what he calls the “negative evidence” – translation: the lack of evidence – that McLain is either at the north end of Houston Street (as the acoustic evidence dictates) or at the south end (as the photographic evidence proves). According to Thomas, it is all still a mystery that remains to be solved.

The reality of course, as detailed in my 2007 report, is that the available photographic evidence overwhelmingly demonstrates that McLain is at the south end of Houston Street and not where the acoustic evidence demands he be at the time of the shooting.

Credible Analysts

With regard to the early synchronization work of researcher Greg Jaynes, Mr. Thomas writes:

“…Myers’ new analysis reemphasizes that [Greg] Jaynes was wrong, inasmuch as in Myers analysis H-20 is the equivalent of Z-138. Yet, Myers cites Jaynes as among the “credible analysts” whose work contradicts those of [Gary] Mack and myself…”

In my section on the history of the acoustics issue, I mentioned the early work of Richard E. Sprague, Todd W. Vaughan, Sim Heninger, Greg Jaynes, and Paul Seaton, all of whom noted the apparent overlap of the Zapruder and Hughes films based on the movements of the Vice Presidential Secret Service Follow-up Car. [24] I also noted that all of these early studies involved “eyeballing” the two films and that none of these individuals “offered a comprehensive scientific analysis or a definitive conclusion” to the issue. [25]

Jaynes concluded, from simply “eyeballing” the two films, that Hughes frame H633 (Jaynes labels this frame H20 for his project) was the equivalent of “around frame 160 plus,” and thus McLain couldn’t have been in a position to transmit the “impulse sounds” thought to be gunshots by the HSCA acoustic experts.

While Greg Jaynes was correct about the end result (McLain wasn’t in the proper position to transmit the sounds of shots), he was incorrect about the specific synchronization point. This is completely understandable given the fact that Jaynes was simply “eyeballing” the two films. The correct answer is that Hughes frame H633 corresponds to Zapruder frame Z135 (not, Z138 as Thomas incorrectly claims). [26]

As for Thomas’ remark that I cited Greg Jaynes “among the ‘credible analysts’ whose work contradicts those of [Gary] Mack and myself,” you’ll note that Thomas put quote marks around the phrase “credible analysts” which is used to denote the exact verbiage I reportedly used to describe Greg Jaynes. This is completely false. At no time does the phrase “credible analysts” appear in the 179-page report. The word “analysts” doesn’t appear at all, and the word “credible” appears only once in relation to anything connected with Mr. Thomas. Here’s that passage:

“…Despite the tremendous weight of credible voices who have denounced the HSCA’s acoustic work acoustically over the years, the thin voices of a few skeptics, like Thomas, continue to find an audience…” [emphasis added]

This is a reference to the acoustic denunciation of Thomas’ work by physicists R. Linsker, Richard L. Garwin, Herman Chernoff, and Norman F. Ramsey in Science & Justice, in which they demonstrated that Thomas continues to draw conclusions based on unreliable dispatcher annotations; misunderstands and misrepresents the physicists’ analysis; and wrongly claims that their analysis supports his conclusions.

There is nothing about Greg Jaynes in the above paragraph. Nada. Under normal circumstances, I wouldn’t bother with the kind of sin Thomas commits in his misuse of quotation marks; however, there is a disturbing pattern to Thomas’ style of argument; one that relies on falsehoods, misleading statements, errors in fact, and mischaracterizations. This is not a minor point. It cuts to the heart of who has credibility on the acoustic issue as it relates to the photographic evidence.

The Acoustical Hypothesis

Mr. Thomas further charged that my 2007 report failed to faithfully articulate the acoustic hypothesis, writing:

“…In order to constitute a serious test of the acoustical hypothesis, such critics as Jaynes and Myers were obligated to present that hypothesis in an accurate and cogent manner and they never do…”

This is absolute nonsense. I won’t speak for Greg Jaynes, but I can say that my hypothesis and that of the HSCA was spelled out on page 10 of my 2007 report:

“…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.

”This research paper documents the use of computer technology, epipolar geometry, and nine amateur 8mm films of the assassination to construct a synchronized photographic record of the shooting and determine the validity of the HSCA’s acoustic evidence of conspiracy.

”The result is a definitive photographic record of the last 40-seconds of President Kennedy’s life that demonstrates that no police motorcycles – including, Officer H.B. McLain’s – were near the area designated by the HSCA’s acoustic experts, and consequently, the committee’s acoustic evidence of a conspiracy in the Kennedy assassination is invalid…”

What essential part of my hypothesis or the HSCA’s acoustic hypothesis was not presented? Apparently Mr. Thomas is referring to his own hypothesis (and one that has been presented in various forms over the years by chief acoustic advocate and Thomas advisor, Gary Mack), which Thomas offers up in his critique in the form of an illustration and a caption, writing,

“The acoustical hypothesis is here presented so that it can be tested against the films.”

Come now, Mr. Thomas knows full well that his hypothesis has been tested against the photographic record and has failed miserably. Indeed, the central points of his hypothesis were presented (in his own words), examined, and shown to be in complete conflict with the photographic record and other physical evidence in Appendix IV of my 2007 report – the same report that Mr. Thomas warns his readers to avoid.

Again, I invite you to read what Mr. Thomas has written on the subject of acoustics and the photographic record, and then read what I wrote in my 2007 research paper.

The Motorcycle Slowdown Before the Shooting

The Thomas hypothesis of H.B. McLain’s path through Dealey Plaza is presented in the form of an illustration which accompanies his recent critique. (See: Figure 2)


Figure 2. Thomas-created illustration depicting his hypothesis of the movements of H.B. McLain at the time of the shooting.


In his illustration, Thomas uses small round circles to represent McLain’s path along Houston and Elm Streets in 1 second increments.

In a caption accompanying his illustration, Thomas claims,

“…just two seconds before the first putative shot the motor noise decreased sharply (75%), indicating that the officer had released the accelerator…”

According to BBN the “first putative shot” occurred at 137.7 seconds. In their report, BBN noted that “In the region of 132 to 133 [seconds], we can see the amplitude of the [motorcycle] noise slowly drop.” [27]

In other words, 4.7 to 5.7 seconds before the first shot, the sound of the motorcycle engine drops in volume, indicating what BBN and others deduce is a possible reduction in speed.

You can actually see this drop in volume in the waveform of the Dallas police recording. (See: Figure 3)


Figure 3. Waveform audio signal image of period immediately before the “first putative shot” at 137.7 seconds as described by BBN. Note the volume drop beginning 4.7 to 5.7 seconds before the “shot.” Thomas describes this decrease in volume as beginning 2 seconds before the “shot.”


Mr. Thomas falsely reports this reduction in volume occurring “just two seconds before” the first shot. The illustration accompanying Thomas’ critique also shows a two second slowing of the motorcycle just before the first shot (indicated by the spacing of circles meant to represent the motorcycle’s trajectory in 1 second increments).

Of course, if McLain were slowing his motorcycle in the five seconds before the first shot, as the Dallas police tape indicates, then he couldn’t have been speeding north on Houston Street during the same period, as Mr. Thomas theorizes. Hence, we get Thomas reducing the slowdown period from 5 to 2 seconds, leaving McLain three seconds to cover the distance between his last known position (as seen in the Hughes film) and the location from which the first shot was allegedly transmitted, per the HSCA.

In the world of Mr. Thomas, if you ignore the photographic record (which shows McLain has only 0.546 seconds available, not 3 seconds) and you ignore the Dallas police audio recording (which shows the motorcycle slowing over a 5 second period, not 2 seconds), any proposed scenario is possible.

The Bond 4 Photograph

According to this same illustration, Mr. Thomas hypothesizes that it took H.B. McLain 22 seconds to traverse the distance between his alleged position at the time of the fatal head shot (represented by the letter ‘b’) and the time of a photograph made by Wilma Bond (the fourth in her series) (represented by the letter ‘c’).

Of course, Thomas must know that it took longer than 22 seconds for McLain to traverse the distance between the head shot and Bond No.4, because Thomas himself has both spoken and written about this very issue.

For instance, Thomas told a 2001 JFK/Lancer Conference audience that McLain reached the position shown in the Bond photo “around 27 seconds after the head shot.” [28]

This was based on Thomas’ estimate of the correlation between the Zapruder film, the Dave Wiegman film, the Mark Bell film, and the Bond photograph. The Wiegman and Bell films both show spectator Charles Hester standing up after the shooting, which provides a point of synchronization. The Wiegman film shows the presidential limousine just before it enters the Triple Underpass, which also figures into correlating McLain’s arrival in Bond.

Mr. Thomas reasoned, “Because the frame in the Wiegman film showing the limousine can occur no later than 8 sec after the head shot, Hester must have stood up no later than 23 sec after the President was shot in the head. Assuming that Bell stopped for about 4-5 sec, allows us to estimate that McLain reached the position shown in the Bond photo at around 27 sec [29] after the head shot.” [30] Now, Thomas tells us that the Bond photograph was not taken 27 seconds, but 22 seconds after the head shot. Which is it?

My own synchronization of the assassination films demonstrates that Bond No. 4 was actually exposed 31.3 seconds [31] after the head shot, not 22 seconds as Thomas hypothesizes in his critique.

So what is the significance of this?

The distance along Elm Street between McLain’s alleged position at the time of the fatal head shot and McLain’s position at the time of the Bond photograph is 188.92 feet.

If McLain takes 22 seconds to travel 188.92 feet, as Thomas believes, then McLain would be moving at 8.59 feet/sec (5.9 mph), [32] a speed Thomas believes is “consistent with the police tape which indicates that the motorcycle idled for about 30 sec after the last shot.”

However, Thomas’ estimate of 22 seconds is wrong – the actual time period between the head shot and the Bond photograph is 31.3 seconds. Mr. Thomas’ calculation also doesn’t take into account the fact that the alleged motorcycle with the open microphone was moving at 11 mph between the last two shots; or that the Mark Bell film shows McLain moving at 10.5 mph just before the Bond photograph was made.

When the additional time and the two known speeds are considered, McLain’s speed between the last shot (believed to be at Z326, according to Thomas) and his appearance in the Bell film – a period of 26.49 seconds over a distance of 114.5 feet – equates to an average speed of 4.32 feet/sec (2.9 mph). The reality, of course, is that McLain’s average speed would be less than 2.0 mph when the speed changes are factored in.

As I reported in my 2007 report, any speed less than 5 mph would require the rider to place both feet on the ground to keep the motorcycle upright. [33] In essence, McLain would had to have stopped or come to a near stop during the 20-plus seconds immediately after the last shot – something that seems rather unbelievable given the circumstances, the audio relied on by Thomas, and McLain’s testimony.

The Hughes Camera Position

One of the principal reasons Mr. Thomas cites for dismissing my photographic work, and one of the four reasons mentioned at the beginning of his critique, is his claim that my estimates of the position of the motorcade vehicles on Houston Street and their speed as they head north are incorrect. According to Thomas, I “badly misplaced Hughes” when determining the location of his camera. Thomas writes:

“…Myers places Hughes 15.5 ft west of the center line of Houston Street and 8.8 ft south of the center line of Main Street. The first value is accurate but the second is not. It places Hughes in line with the traffic stripe separating the inner and middle east bound lanes of Main street (and Myers’ illustrations e.g. exhibit 83, show this). Actually Hughes was in line with the traffic stripe separating the middle from the outer lanes, which can be seen in the segment of the Hughes film of the oncoming motorcade on Main Street. This error results in a displacement of approx. 11 ft. from where Myers places him (see Fig. 6 for orientation)…”

Figure 4 below is Hughes frame H223, the first frame depicting the motorcade heading west on Main Street, coming toward Hughes’ position. Notice the two white road stripes south of the yellow center-line, separating the two eastbound lanes of travel and the parking lane. Hughes is obviously positioned exactly where I describe – i.e., directly in line with the white road stripe that is immediately south of the yellow center-line.


Figure 4. Hughes frame H223 showing Hughes’ camera position to be in-line with the white road stripe (arrow) immediately south of the centerline.


Subsequent frames demonstrate that Hughes’ maintains this position throughout his film sequences. Furthermore, a still image taken by Charles Bronson (See: Figure 5) shows that Hughes is standing with a group of spectators ringing the turn at Main and Houston.


Figure 5. Bronson slide depicting spectators ringing the turn at Main and Houston.


If Hughes were standing 11 feet further south (as Thomas claims), he would be behind the line of spectators and thus would have an obstructed view of the motorcade. We know from his film that Hughes had an unobstructed view, and therefore was not standing further south in the crowd, as Thomas claims.

Bottom line? Thomas is wrong. There is no error in the placement of the Hughes camera.

Displacement of the Motorcade

Another one of the principle reasons Mr. Thomas cites for dismissing my photographic work is his claim that I failed to consider the effect that moving Hughes’ camera would have on the time available to McLain to traverse Houston Street. Thomas writes:

“…Assuming that Myers’ line of sight estimates of the cars relative to inanimate objects is done correctly then the 11 ft northward displacement of Hughes must cause the cars to be similarly displaced from actual by about the same distance. If so it lops another 1-1/2 sec off the timeline available to McLain to arrive at the required position, because that is how long it would take the motorcade to move up 11 ft…”

First, Mr. Thomas needs a math lesson. A motorcade vehicle traveling at a speed of 8 to 10 mph would cover 11 feet in 0.75 to 0.94 seconds, not 1.5 seconds as Thomas claims. [34]

Second, and more importantly, it doesn’t take a mental giant to see that Thomas’ central argument here is completely bankrupt. Figure 6 below demonstrates that a line-of-sight drawn between the southwest corner of the Dal-Tex Building and Hughes’ camera position will displace objects at different rates depending on their position along that line-of-sight.


Figure 6. Geometric plot of 11 foot southern displacement of Hughes’ position.


For instance, at the point of the camera, the displacement would be the same as the camera (11 feet, according to Thomas’ example). On the other hand, the displacement near the corner of the Dal-Tex Building would be minimal (2.5 inches in this example).

But Thomas is not talking about the displacement of objects at the location of the camera or near the corner of the Dal-Tex Building, is he? No, Thomas is talking about the alleged displacement of motorcade vehicles traveling north on Houston Street, a point that lies nearly equidistant between the camera and the Dal-Tex Building.

The example below (See: Figure 7) shows this displacement to be 6.5 feet, about half the amount claimed by Thomas. At a motorcade speed of 8 to 10 mph, this distance would equate to a time displacement of about 0.5 seconds, not 1.5 seconds as Thomas claims.

None of this really matters, of course, since Thomas’ claim that the Hughes camera position was in error is false. (See: Figure 4 above)


Figure 7. Result of 11 foot southern displacement of Hughes’ position on perceived location of motorcade vehicles moving north on Houston Street.


Speed of the Motorcade Vehicles

To further challenge my synchronization of amateur films related to acoustics, Mr. Thomas falsely claims that my 2007 report reported the motorcade moving at “relatively steady speeds,” writing:

“…But Myers’ estimates of the vehicle speeds are also suspect. He calculates that the motorcade vehicles were moving at relatively steady speeds of around 8-10 mph on Houston Street…”

Mr. Thomas seems to be the only one that doesn’t know that many variations in motorcade speed were discussed and documented throughout my 2007 paper.

For instance, investigation shows Camera Car 1 initially heading north on Houston Street at a speed of 8.7 mph (page 65) then accelerating to 9.5 mph (pp.62-63) as it reached the midpoint between Main and Elm. Likewise, it was demonstrated that Camera Car 2 turned from Main onto Houston at 7.1 mph (page 61, 65-66), accelerated to a speed of 8.1 mph (page 66), and continued to accelerate to a speed of 9.1 mph (page 66) by the time it reached the midpoint between Main and Elm. In another example, the National Press Pool Car was demonstrated to be initially traveling north on Houston at 7.8 mph (page 119, 124), decelerated to 7.3 mph (page 121, 124), accelerated to 9.3; and continued accelerating to a speed of 9.9 mph (page 119, 124). In yet another example, Dallas police motorcycle officer Marion L. Baker’s motorcycle was shown to be traveling at 7.0 mph (page 69), then accelerating to a speed of 8.7 mph (pages 69-71) as he traveled north on Houston.

There are more examples 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. I have never suggested or claimed that the vehicles in the motorcade were moving north on Houston Street “at relatively steady speeds of around 8-10 mph,” as Thomas claims.

Mr. Thomas makes this same charge again later in his critique, writing:

“…In contrast to Myers’ reconstruction which has the cars moving at a steady 9 mph on Houston Street, I have argued that the motorcade is moving in accordion fashion, slower through the turns than in the straight-aways, and moreover are traveling in a slow and surge mode…”

This is a complete mischaracterization of my work and the written results which demonstrate time and again as I’ve already shown that the vehicles in the motorcade moved at varying speeds, independent of each other, and in accord with what one would expect in a parade of this type. Anyone who reads the report I made available in June, 2007, will see that Mr. Thomas’ accusation is, to put it politely, false in every sense of the word.

In a attempt to buttress his argument, Thomas cites a passage from James C. Bowles’ 1979 report, “The Kennedy Assassination Tapes: A Rebuttal to the Acoustic Evidence Theory,” as published on page 325 of Gary Savage’s 1993 book JFK: First Day Evidence. Bowles wrote:

“…McLain and others estimated the motorcade speed on Houston as no more than 2 or 3 mph, when they were moving… vehicles which had just made their way slowly off Main onto Houston were now slowing and stopping again… Other vehicles were barely moving if not stopped.”

Mr. Thomas then adds,

“…Thus any instantaneous measurement of speed of the cars in motion is only a snapshot which is not applicable to the entire interval between the end of the Hughes film and the later view of the cars in the Zapruder film. Bowles further argued that the cars were not ‘coaches in a train.’ But the ‘coaches in a train’ model is exactly what Myers’ uses for his reconstruction and then rebukes me for suggesting that there could be ambiguity in these extrapolations…”

First, Mr. Thomas’ argument that a “snapshot” of the speed of some motorcade vehicles as seen at the end of 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” early in his critique) fails to take into account that both films depict the motorcade moving north on Houston Street in a continuous fashion.

In addressing this issue, Thomas writes that some police officers recalled the motorcade moving in “a stop and go” manner (Thomas doesn’t specify the officers or the time period referred to), suggesting of course, that some of the motorcade vehicles may have stopped (or slowed considerably) during the few seconds when they were not being captured by either the Hughes or Zapruder cameras.

But, how can this be? 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. 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, as Thomas suggests) simply because the vehicles which are in the camera’s view are seen moving forward in a normal manner.

What does Mr. Thomas think is happening off-camera? Does he imagine some motorcade vehicles piling into each other like some comic version of carnival bumper-cars?

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

The photographic record is conclusive on this point. The Hughes film depicts vehicles in the motorcade moving north on Houston Street in a continuous fashion until the film ends at the equivalent of Zapruder frame Z185. The Zapruder film, which overlaps the last 2.84 seconds of the Hughes film, also depicts the procession moving forward in a normal manner. The position of any particular vehicle during those brief seconds when they do not appear in either film can be extrapolated from the known speed and position of those same vehicles when they are seen.

The results of those extrapolations are consistent with the continuous forward progression of the parade and do not suggest in any way that the motorcade as a whole or that any individual vehicle within the motorcade stopped or slowed to any appreciable degree as they made their way north on Houston Street. Frankly, this is common sense, something that seems to have eluded Mr. Thomas.

Second, I have never suggested that the motorcade vehicles were traveling in tandem as if ‘coaches in a train,’ and Thomas surely knows it. This is not just a mischaracterization of the results of my work, it is a flat out lie, one easily demonstrated not only elsewhere in this article, but in page after page after page of my 2007 paper. Read it and judge for yourself.

What I condemned in my 2007 report was both the HSCA’s and Thomas’ insistence that the open microphone was moving at a speed that was consistent with the average speed of the presidential limousine – reportedly 11.3 mph – at the time of the shooting. Thomas considered this fact significant, explaining, “This is an impressive coincidence…Thus, the topographic order in the matching data [35] is in remarkably close accord with the working hypothesis that a police motorcycle with an open microphone was traveling in the motorcade...”

I pointed out what James C. Bowles did in his own rebuttal – the motorcade vehicles were moving at varying speeds (between 7.1 and 12 mph) during the shooting. [36]

Speed of the Secret Service Car

The only specific example Mr. Thomas offers to support his claim that I miscalculated the speed of the motorcade vehicles, and consequently my synchronization of amateur films was inaccurate, are calculations surrounding the speed of the Vice Presidential Secret Service Follow-Up Car. Thomas writes:

“…Most importantly (on p. 49) he calculates the speed of the Secret Service car [the seventh in the motorcade] at 8.7 mph. But the speed of the car is only 6.5 mph. In the Zapruder film the front bumper of the SS Car comes in to line with a lady dressed in red standing on the corner underneath the signal light at Z-144. The corresponding rear bumper reaches the lady in red 34 frames later at Z-178. That is, at 18.3 frames per sec it takes the SS car 1.86 sec to go one car length. With a length of 215 inches, about 17.9 ft, it has a speed of 9.6 ft. per sec, which equals 6.5 mph…”

The portion of the text referenced by Mr. Thomas on page 49 of my 2007 report calculates an estimate of the speed of the Vice Presidential Secret Service Follow-Up Car (the seventh car in the motorcade) in order to determine how much time elapsed between Hughes frame H631 and Zapruder frame Z150.

In the 2007 report, I wrote, “That unknown time period [i.e., the period between H631 and Z150] can be determined by using the two known speeds immediately before and after that period. For instance, the speed of the Secret Service vehicle immediately prior to Hughes frames H631 was determined to be 13.58 feet/sec (9.3 mph); while it’s speed immediately after Zapruder frame Z150 was found to be 11.87 feet/sec (8.1 mph). Using these two known speeds, the average speed of the Secret Service vehicle between Hughes frame H631 and Zapruder frame Z150 can be calculated as 12.73 feet/sec (8.7 mph).” [37]

Mr. Thomas claims that I calculated the speed of Secret Service car at 8.7 mph when in fact it should have been 6.5 mph. However, Thomas is wrong on two fronts.

First, the 8.7 mph calculation was the average speed of the Secret Service car between Hughes frame H631 and Zapruder frame Z150, not the speed of the car between Zapruder frames Z144 and Z179, from which Thomas derived his 6.5 mph figure.

In fact, as I demonstrated, the Secret Service car was not moving at a steady 8.7 mph, as Thomas suggests, but was decelerating as it made its turn from Houston onto Elm Street, moving from 9.3 to 8.7 to 8.1 mph.

Comparing my 8.7 mph average speed at one point in time with his 6.5 mph figure at another point in time is akin to Thomas comparing apples and oranges.

Second, and more importantly, the 6.5 mph figure used by Mr. Thomas is incorrect. Figure 8 below demonstrates that the Secret Service car – a 1963 Mercury Monterey – passed the Houston Street spectator (dressed in red) over the course of 32 frames – not 34 frames as Thomas claims.

This can clearly be seen by counting how many frames it takes the Secret Service car to pass the spectator in red. Using the driver’s side of the vehicle, you can see the 17.9 foot long vehicle pass the spectator between Z148 and Z180 – a total of 32 frames. Thomas’ mistake was to use the obscured passenger side of the vehicle to make his measurements, rather than the unobstructed driver’s side.



Figure 8. Stabilized Zapruder film sequence – Z148-180


In short, it takes 1.75 seconds (32 frames ÷ 18.3 fps = 1.75 sec) for the Secret Service car to traverse its own length. Simple math shows this to be a speed of 10.23 feet/sec, or 7.0 mph – not 6.5 mph, as Thomas calculates.

During the course of investigating Thomas’ claims, I discovered two minor errors [38] in my report that relate to this issue. First, the 8.7 mph figure which appeared in the text on page 49 should have been 8.4 mph. Exhibit 19 (page 48) correctly showed the average speed between H631 and Z150 as 12.73 feet/sec, which equates to 8.4 mph – not 8.7 mph as mentioned in the body of the text.

Second, the speed of the Secret Service car between Zapruder frames Z150 and Z176 was reported as 11.87 feet/sec, or 8.1 mph. This is incorrect. The Secret Service car traveled a distance of 15 feet between Z150 and Z176. This equates to a speed of 10.56 feet/sec, or 7.2 mph.

The average speed of the Secret Service vehicle between Hughes frame H631 and Zapruder frame Z150 is therefore re-calculated to be 12.07 feet/sec (8.2 mph).

Does this affect the synchronization of the Zapruder film and the Hughes film, estimated to synchronize at H684/Z150? The simple answer is, no.

At the average estimated speed of 12.07 feet/sec (8.2 mph), the Secret Service vehicle would have traversed the known distance of 11.5 feet between Hughes frame H631 and Zapruder frame Z150 in 0.95 seconds; or, the equivalent of 17.4 frames (at 18.3 fps). Hughes frame H631 plus an additional 17.4 frames equates to Hughes frame H648. Hence, Hughes frame H648 remains the equivalent of Zapruder frame Z150 (+/- one frame), as originally reported.

For those who prefer to argue that the speed of the Secret Service car as derived from Zapruder frames Z148-180 (i.e., 7.0 mph) is more accurate than an estimate gleaned from the distance the car traveled between Zapruder frames Z150-176 (i.e., 7.2 mph), we find that at an average estimated speed of 11.91 feet/sec (8.1 mph), the Secret Service vehicle would have traversed the known distance of 11.5 feet between Hughes frame H631 and Zapruder frame Z150 in 0.966 seconds; or, the equivalent of 17.7 frames (at 18.3 fps). You’ll note that this result is still within the error rate of (+/-) one frame, mentioned above and throughout my 2007 report.

The end result is that the speed of the Secret Service vehicle as recorded in the Zapruder film does not undermine my photographic analysis, as Thomas claims, but supports it, strengthening the case that the acoustic evidence of conspiracy is invalid.

Shaving Time

Mr. Thomas summarizes his claim that my 2007 report shaved 3.5 seconds off of the time available to McLain this way:

“…Through this combination of errors: setting the first shot earlier than it was, displacing the vehicles farther northward than they were, and having them travel faster than they were, Myers lops about 3-1/2 sec off the timeline of events…”

As shown above, and demonstrated in my 2007 report, the first shot was reportedly fired at about Z160, not Z175 as Thomas continues to opine; [39] there is no displacement error in positioning the motorcade vehicles, as Thomas falsely claims; and the vehicles were not calculated as traveling faster than the films warrant, as Thomas also falsely claims.

Consequently, H.B. McLain does not have an additional 3.5 seconds to reach the first shot position dictated by the acoustic evidence.

Ambiguity of the Photographic Record

Many of the arguments Mr. Thomas presents in his critique of my 2007 report rely on his belief that the photographic record and what can be extrapolated from it are ambiguous at best. He writes:

“…A precise estimate of the exact amount of time that McLain has between his last filmed position and the time of the first shot may not be attainable because it depends very much on how reliably one can extrapolate the speed of the motorcade. Because at these speeds it can take about two seconds to move one car length, it is clear that over distances of several car lengths any extrapolation is bound to have an ambiguity of at least a second or two…”

My work on the photographic record demonstrates three things definitively and beyond any doubt: (1) the amount of time McLain has to reach the first shot position can be determined exactly (+/- one frame or 1/18th of a second); (2) the speed of the motorcade can be extrapolated accurately and reliably; and (3) any error is minimal, falling within 1/18th of a second.

The only ambiguity in the photographic record is the fuzziness that conspiracy advocates like Mr. Thomas insist on injecting into the debate with false accusations and misleading statements. At other times, they simply ignore the photographic record.

McLain’s Rate of Travel

For instance, Mr. Thomas insists that McLain has plenty of time to reach the first shot position at a reasonable speed, writing:

“…To put the analysis in proper perspective consider these time estimates. Myers calculates McLain’s speed as he makes the turn from Main on to Houston at 14.7 mph. McLain is last seen at 174 ft from the acoustically required position. At a speed of 10 mph, the equivalent of 15 ft per sec, it would take him about 11 seconds to cover the distance. At 20 mph (=30 ft per sec) he could cover the distance in 5.8 sec. Thus at speeds of 21-29 mph, the distance could be covered in just 3-5 sec. Just from the obvious errors in Myers’ analysis one can see that McLain had the necessary time…”

Mr. Thomas’ entire argument here hinges on McLain actually having 3 to 5 seconds available to him to travel the required distance. Yet, the photographic record demonstrates that McLain only has 0.546 seconds (assuming a first shot at Z160, as the HSCA concluded) or 1.37 seconds (assuming a first shot at Z175, as Thomas insists). In either case, it would be impossible for McLain to cover 174 feet, especially when one considers the required acceleration and deceleration necessary to match McLain’s known speed both before and after the period in question. All of this was detailed in my 2007 report (pages 51, 144-145), which Thomas ignores.

Let’s be very clear: The issue at hand is not whether McLain could cover the distance given a reasonable amount of time. The issue is whether McLain could cover the distance in a very small, specific amount of time as dictated by the photographic record. Mr. Thomas seems to want to pretend the photographic record doesn’t exist.

The Consistency of the Photographic Record

Mr. Thomas also alleges that my conclusion that the photographic record demonstrates a consistency in the motorcade’s movement is questionable, writing:

“…Although Myers claims that his measurements are consistent among the other films, the other films do not show the same vehicles in the same positions. And his conclusions based on the other films are also questionable…”

First, I found the movement of the various motorcade vehicles to be entirely consistent throughout the filmed record as they made their journey through Dealey Plaza. In other words, the motorcade vehicles travel in a normal, physically possible and consistent manner as they move from camera to camera making their way through Dealey Plaza. This is not a “claim” pulled out of thin air, as Mr. Thomas characterizes it, but a fact as documented in great detail in my 2007 research paper.

Second, I examined nine amateur films and one professional film that covered the period beginning 40.22 seconds before the head shot and ending 9.45 seconds after the head shot (a total of 49.67 seconds). During that period there was only one moment, lasting 1.4 seconds, in which no cameras were operating. In most cases there were two or more cameras operating simultaneously. For instance, of the 49.67 second time period examined, 45.11 seconds were covered by at least two cameras, 25.33 seconds were covered by at least three cameras, and 15.78 seconds were covered by 4 cameras.

Mr. Thomas’ blanket charge that the films I examined do not show the same vehicles in the same positions is false, as demonstrated in the “Amateur Film Synchronization Timeline” that appears in Appendix III (pp.106-116), which depicts the presidential limousine, the Secret Service follow-up car, and the vice presidential car as they turn from Main onto Houston Street from four different camera viewpoints.

I can only guess (since he doesn’t specifically say) that Thomas’ chief complaint is that some of the motorcade vehicles seen in the background of two specific films – the Hughes and Zapruder films – are offset in time by a few seconds and therefore do not show the vehicles moving north on Houston Street at the exact same moment.

While this is true, Thomas chooses to ignore the fact that the offset between the two films has no effect on the extrapolation of motorcade speed and position since (a) the presidential limousine and the seven vehicles that trail it are visible in both films as they travel north on Houston and turn onto Elm Street, (b) all vehicles are in continuous motion, (c) the distances traversed are known through geometric triangulation, (d) the individual speeds of the vehicles are known based on camera rates (relative to Zapruder’s camera), and (e) the only gap in the film coverage is a period of just 1.4 seconds. [40]

All of this information permits the location and speed of the motorcade during the offset period to be easily, reliably and accurately extrapolated from the known record.

The synchronization of the filmed record (including extrapolation of the speed and position of some vehicles during brief periods) results in a continuous photographic timeline that is consistent in its depiction of both the speed and position of the motorcade’s journey through Dealey Plaza – a timeline that is accurate to within 1/20th of second, as proven by the independent synchronization (both visual and geometric) of all nine amateur films as well as still photographs taken during this same period.

Mr. Thomas offers nothing to challenge this central conclusion, nor does he present any facts to support his suggestion that the consistency of the photographic timeline I reconstructed is suspect, or that the conclusions I arrived at are “questionable.”

The Dorman Film - McLain or Coursen?

Mr. Thomas also challenges the identification of H.B. McLain as the motorcycle officer depicted at the end of the Dorman film, writing:

“…Myers does not provide any evidence that would distinguish McLain from Coursen. For example, the cop in Dorman has a ticket book visible through the windshield and Myers cited this feature as an identifying character for officer McLain. But Figure 7 shows another motorcade officer (Chaney) with his ticket book in the same position; thus having a ticket book in this position was certainly not unique to McLain, and there is no information on where Coursen kept his ticket book…”

The “ticket book” referred to by Mr. Thomas appears in a photograph of motorcycle escort James Chaney as he turns from Main onto Houston. That photograph shows a light or white-colored object (you have to take Thomas’ word for it that it is a “ticket book”) lying between the handlebars and behind the windshield.

H.B. McLain, on the other hand, testified that he fastened his “paper work” to the inside of the motorcycle’s windshield with two clip holders. This was one of several identifying characteristics which allowed McLain to identify his motorcycle from others used by the police department. This fact appears in my 2007 report (p.92) along with two high quality photographs taken before and after the assassination which show this unique feature of McLain’s motorcycle. (p.91)

The two photographs show a collection of loose papers clipped at an oblique angle to the inside lower-left corner of McLain’s windshield. The collection of papers is obviously not a “ticket book,” as Thomas claims. Nor are they even in the same position as a simple comparison demonstrates. (See: Figure 9)


Figure 9. Comparison of shape and position of McLain’s “paper work” (left) and Chaney’s “ticket book” (right).


Of course, none of this means much, since Thomas is not alleging that Chaney is the officer seen at the end of the Dorman film. And even if he were, the distinct differences between Chaney’s “ticket book” and McLain’s “paper work” would rule Chaney out.

It is true that as of this date there are no known photographs of J.W. Coursen’s motorcycle (Coursen was nearly 400 feet behind the president’s limousine) taken on the day of the shooting that are clear enough or that show the area in question needed to resolve the issue of whether or not Coursen had papers clipped on his windshield just like McLain did.

However, it is incumbent upon Thomas to prove that Coursen had “papers” pinned to the inside lower-left corner of his windshield just like McLain, not base his entire theory that Coursen is the officer in the Dorman film on the unsupported allegation that Coursen could have had “papers” pinned to his windshield.

For my part, I presented a substantial amount of direct and circumstantial evidence [41] that strongly supports my conclusion that the motorcycle cop in the Dorman film is H.B. McLain, including these salient points:

(1) The motorcycle officer in the Dorman film is seen riding on the left side of motorcade between Camera Car 3 and Congressional Car 1 – the same relative position occupied by McLain throughout the entire motorcade and the precise position occupied by McLain just twelve seconds earlier, as depicted in the Hughes film.

(2) The motorcycle officer in the Dorman film has a white object attached to the inside lower-left corner of his windshield. A similar white object is visible on McLain’s motorcycle twelve seconds earlier, as depicted in the Hughes film. McLain testified that this white object was “paper work” clipped to the inside of the windshield (a fact verified by numerous photographs taken both before and after the assassination).

(3) The trajectory and speed of the motorcycle officer in the Dorman film is consistent with the projected trajectory and speed of McLain’s motorcycle, as depicted in the Hughes film. In other words, McLain’s speed of 14.7 mph as he turns from Main onto Houston (as seen in the Hughes film), his projected average speed of 9.2 mph as he continues north on Houston Street (based on the time available and the distance traveled; a speed consistent with the speed of other motorcade vehicles along this portion of the route), and the motorcycle officer’s speed of 7.9 mph (as seen in the Dorman film) are consistent with that of a single individual – H. B. McLain.

Mr. Thomas finds all of this hard to believe. In order to keep the acoustic evidence alive and valid, Thomas must cling to the idea that H.B. McLain and J.W. Coursen, without any instruction or provocation, gunned their motorcycles before the shooting even began, and rocketed at impossible speeds to a point 180 feet ahead of their assigned position – remember, now, that these are the assigned positions they occupied (within a car length) for the previous 39 minutes – in time to transmit the sound of gunfire (McLain) and appear in the Dorman film (Coursen).

Despite an avalanche of contrary evidence presented in my 2007 report (including the entire photographic record), Mr. Thomas finds this scenario logical and credible.

J.W. Coursen’s Account

Mr. Thomas further claims that my own synchronization of amateur films supports his contention that the motorcycle officer seen at the end of the Dorman film is J.W. Coursen and not McLain, writing:

“…Myers claims that [Coursen] does not reach the intersection in time to see [Mrs. Kennedy and SS Agent Hill on the trunk of the limousine]. But this claim is not supported by his synchronization… By Myers' own account (on p.103) the motorcycle cop appears in the last 40 frames of the Dorman film which he calculates to be equivalent to Z-frames 367-411. During those last frames the cop is at the intersection well beyond the wall which was the only inanimate obstruction to his view of the limousine. Thus, it is not at all clear how Myers can assert that the cop was not in a position to have seen Mrs. Kennedy and Agent Hill on the trunk as Courson said he did…”

The unique identifying characteristics of McLain’s motorcycle, his relative position in the motorcade procession on Houston Street as depicted in both the Hughes and Dorman films (which is consistent with his position throughout the entire period of the motorcade), and the consistency of his speed and trajectory in the Hughes film with that of the motorcyclist in the Dorman film is nearly conclusive evidence that the motorcycle officer in the Dorman film is in fact H.B. McLain.

I say “nearly” because the motorcycle officer in Dorman doesn’t have a sign hanging around his neck identifying him as McLain, but given all of the relevant evidence, do we really need that?

Of course, Mr. Thomas knows that if the motorcycle office seen in the Dorman film is H.B. McLain, then the ballgame is over – McLain could not have arrived at the Elm and Houston Street intersection in time to transmit the sound of the first shot if the Dorman film shows him arriving after the shooting is over. Thus, we get Thomas’ argument that the motorcycle officer in Dorman is someone other than McLain.

Mr. Thomas argues that the motorcycle officer in the Dorman film is J.W. Coursen and not McLain based on Coursen’s 25-year-plus recollections as published in Larry Sneed’s 1998 book No More Silence, including Coursen’s erroneous claim that when he rounded the corner onto Elm he saw the limousine had stopped and a Secret Service agent was helping Jackie Kennedy into the backseat before it took off again. In reality, the limousine never stopped.

J.W. Coursen was interviewed three times over the course of 16 years. During each interview, Coursen described a slightly different version of events. [42] Even Coursen’s third interview, which Thomas embraces as true, contains insurmountable timing problems which I detailed in my 2007 report (p.168) and all of which are conveniently ignored in Thomas’ recent critique.

No, Mr. Thomas prefers to accept Coursen’s third interview as truth simply because it places Coursen at Elm and Houston at about the time the motorcycle officer appears in the Dorman film. So, per Thomas, abracadabra! The Dorman film depicts Coursen!

Mr. Thomas tells his readers that my own synchronization of the amateur films of Kennedy’s death supports his contention, showing the motorcycle officer in the Dorman film arriving just in time to get an unobstructed view of Mrs. Kennedy crawling on the trunk of the limousine, exactly as J.W. Coursen described.

Once again, Mr. Thomas’ offers a hollow argument to support his hypothesis. On page 103 of my 2007 report, I demonstrated that the last frame of the Dorman film, which shows the motorcycle officer arriving at the corner of Elm and Houston, synchronizes to Zapruder frame Z411. The Zapruder film shows Mrs. Kennedy climbing out onto the trunk of the presidential limousine and returning to her seat between Zapruder frames Z340 and Z425 (a period of 4.7 seconds). At Zapruder frame Z411, Mrs. Kennedy was less than a second away from being back in the limousine.

Mr. Thomas writes, “…During those last frames the cop is at the intersection well beyond the wall which was the only inanimate obstruction to his view of the limousine…”

As Figure 10 below demonstrates, the motorcycle officer seen in the Dorman film did not have an unobstructed view of the limousine at D496/Z411. Mr. Thomas seems to forget that Elm Street curves to the south and away from the motorcycle officer’s position, the turn onto Elm being 120 degrees, not 90 degrees as Thomas suggests.


Figure 10. Line-of-sight from motorcycle to limousine at Dorman frame D496.


A line-of-sight drawn between the motorcycle officer’s position at D496/Z411 and the limousine at that same moment proves the officer would have to be looking backward across the reflecting pool retaining wall and numerous other obstructions which make up the decorative structure at the southwest corner of Elm and Houston.

It is also apparent that at the speed the motorcycle officer is traveling (7.9 mph, as shown on pages 93-94 of my 2007 report), the officer wouldn’t clear the retaining wall structures until Zapruder frame Z431 – after Mrs. Kennedy had climbed back into the limousine. Even then, the motorcycle officer would still be looking through a crowd of spectators (See: Figure 11) gathered at the Elm and Houston corner, obstructing any good view he might have of the limousine, locate more than a football field away (353 feet).


Figure 11. Dorman film mosaic showing spectators on the south Elm Street curb.


By the time the motorcycle officer would have cleared Elm Street’s south curb (at Zapruder frame Z467), and the crowd gathered there, the limousine would have entered the deep shadows of the underpass. (See: Figure 12)


Figure 12. Position of limousine when motorcycle clears crowd at Z467.


Obviously, given the physical layout of Dealey Plaza, it would have been impossible for the motorcycle officer depicted at the end of the Dorman film, regardless of his identity, to have witnessed Mrs. Kennedy crawling across the trunk of the presidential limousine from the Elm and Houston intersection. This is not a question of whether Coursen is more credible than McLain, as Thomas suggests, but a matter of physical impossibility.

Direct Photographic Proof

The idea that impossible things can happen on a regular basis in Dealey Plaza is a recurrent theme in each and every one of the contradictory arguments that Mr. Thomas offers up in an effort to rally support for an acoustic solution to the Kennedy assassination – a motorcycle that is accelerating north on Houston (while simultaneously decelerating), a fatal shot from the grassy knoll that leaves no forensic trace, and motorcycle escorts who can see through objects.

Mr. Thomas doesn’t seem to want to accept the simple truth that H.B. McLain couldn’t physically reach the position dictated by the acoustic evidence in the time allotted.

Mr. Thomas 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 this is demonstrably false. The photographic record clearly shows that just 0.546 seconds before the first acoustic impulse (identified by the HSCA acoustic experts to be a gunshot) McLain is over 174 feet from where he has to be in order for the acoustic evidence to be valid. In order to cover that distance in the allotted time, McLain would had to have accelerated his motorcycle to a speed better than double that which the motorcycle was physically capable of achieving. In short, it’s impossible.

And even if the first acoustic impulse is synchronized to Zapruder frame Z175, as Thomas has argued in the past and continues to argue, McLain still cannot cover the distance between his last know position and the first theoretical impulse transmission location in the time allotted. Again, it’s impossible.

This is not just circumstantial evidence that the acoustic evidence is unreliable. This is direct photographic proof that McLain is at a completely different location from where he has to be in order for the acoustic evidence to be valid. And as we all know, no one can be in two places at once, no matter how bad Mr. Thomas wishes it were so.

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.

New Evidence

Mr. Thomas concludes his critique of my 2007 report by writing,

“McLain was either in exactly the right place, near the mayor’s car, or he was way back, no closer than the [twelfth] car, which is where Myers believes he was. The reality is that until some new films or photographs surface, the presently available materials are consistent with either contention.”

Rubbish. The numerous arguments offered by Mr. Thomas that McLain was in exactly the right location to validate the acoustic evidence have been minutely examined and demolished in both Appendix IV of my 2007 report and again here in response to his recent critique. The suggestion that his unsupported opinions hold weight equal to the work behind my 18-month epipolar geometric photographic study and its conclusions is a joke, and a bad one at that.

More important, Mr. Thomas’ claim that only new films or photographs will resolve questions about McLain’s location is nothing short of a desperate attempt to keep the HSCA’s acoustic evidence of conspiracy alive and well for another round of debate. The currently available photographic record is more than adequate to resolve this issue and that record proves the acoustic evidence invalid – in spades.

Mr. Thomas doesn’t seem or want to understand that the cohesiveness of the photographic record cannot be undone by any newly discovered films or photographs simply because any newly unearthed films or photographs cannot contradict the photographic record already available. Any newly discovered films and photographs can only strengthen what we already know to be true.

Fini

While I remain open to any new photographic evidence that can help clarify questions surrounding the acoustics debate, I believe my 2007 paper, “Epipolar Geometric Analysis of Amateur Films Related to Acoustics Evidence in the John F. Kennedy Assassination,” proves 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 in 1979.

Equally evident is the fact that Mr. Thomas’ critique of my work relies on falsehoods, mischaracterizations, and ignorance of the true facts as they relate to the acoustic and photographic record of the Kennedy assassination. [END]


Footnotes:

[1] 8 HSCA 46

[2] 8 HSCA 49-50

[3] 8 HSCA 105

[4] Thomas glosses over a significant issue raised by the 1981 Committee on Ballistic Acoustics (CBA) but to my knowledge not adequately addressed by anyone attempting to defend the acoustic evidence since. Bolt, Beranek and Newman (BBN) matched one of their test shots from the grassy knoll to the impulse patterns on the Dallas police tape beginning at 145.15 seconds. In other words, the muzzle blast of the suspected shot would have occurred at 145.15 seconds followed by its echoes. However, Mark Weiss and Ernst Aschkenasy (WA), the two Queens College experts who refined BBN’s grassy knoll shot data, matched the BBN test shot from the grassy knoll to the impulse patterns on the Dallas police tape beginning at 144.90 seconds, 0.25 seconds earlier than the BBN match (or 0.2625 seconds earlier if tape playback speed corrections of 5% are considered). This is highly significant because both BBN and WA believe each test-shot/test-microphone produces a unique set of muzzle blast/echo patterns. How then could BBN obtain a match at 145.15 seconds and WA obtain a match at 144.90 seconds for the same shot? This isn't a difference of milliseconds that one might dismiss as a consequence of BBN and WA’s different approaches to analyzing the acoustic data. This is the difference of a full quarter second. In short, WA obtained a match to an impulse pattern that was uniquely different than the one BBN obtained, a fact that cuts to the core of the alleged uniqueness of the Dallas police tape impulse patterns. The 1981 CBA noted that the grassy knoll shot identified by BBN and WA was “completely different” as demonstrated by the more than 200 millisecond (or more than 200 foot) displacement between the two identifications. Dr. James Barger, lead scientist for BBN, told the CBA that the difference could be reconciled by assuming that the echo pattern had been subjected to one additional wall reflection. The CBA responded, “Even with this interpretation there remains a serious flaw; namely, that the [BBN] analysis missed the identification that WA considers to be the primary one.” [emphasis added] (CBA Report, p.13) Consequently, the CBA recommended that a detailed analysis be made of the interpretation offered by Barger of the 200 millisecond displacement. (CBA Report, p.94) This has yet to be done.

[5] Myers, Dale K., “Epipolar Geometric Analysis of Amateur Films Related to Acoustics Evidence in the John F. Kennedy Assassination” (Hereafter: Epipolar Report), June 1, 2007, pp.144-45

[6] HSCA Report, p.83

[7] “Unredacted Episode 4: Transcript of Interview with Don Thomas,” April 5, 2006, www.maryferrell.org, p.9

[8] Email, Don Thomas to Paul Hoch, March 31, 2008

[9] 5 HSCA 648

[10] 8 HSCA 80

[11] 8 HSCA 7

[12] Myers, Op. cit., p.149

[13] 8 HSCA 101, Table II

[14] Thomas, Donald B., “Hear No Evil: The Acoustical Evidence in the Kennedy Assassination,” November 17, 2001, Dallas, Texas

[15] 7 HSCA 175-76

[16] 7 HSCA 201

[17] 7 HSCA 210

[18] Rockefeller Commission Report, pp.260, 262, 264

[19] HSCA Report, p.80-81

[20] Ibid, p.81

[21] Myers, Op. cit., pp.149-158

[22] Ibid, pp. 68-76

[23] Ibid, pp. 51, 144

[24] Ibid, pp. 17, 20-21, 23

[25] Ibid, p.23

[26] Ibid, p. 159, 111

[27] 8 HSCA 63

[28] Thomas, Op. cit.

[29] Interestingly, Robert Groden came up with a figure of 28 seconds by estimating that Bell took 10 seconds to wind his camera between sequences. (5HSCA720) In his book, 76 Seconds in Dealey Plaza, Robert B. Cutler estimated that the Bond 4 photograph was taken 20 seconds after the head shot. (Cutler, Robert B., “76 Seconds in Dealey Plaza,” p. 79) Subsequent research convinced him that it was closer to 28-30 seconds.

[30] Thomas, Op. cit.

[31] The Bell film sequence which depicts McLain gliding down Elm at 10.5 mph begins 27.2 seconds and ends 28.2 seconds after the head shot. At that point, McLain was moving at 10.5 mph and was 47 feet from where he is seen in the Bond photograph. Simple math shows that Bond No. 4 was therefore taken 3.1 seconds later (47 feet ÷ 15.4 feet/sec = 3.1 sec), or 31.3 seconds after the head shot.

[32] Thomas incorrectly reports the speed as 4 mph. (Thomas, Donald B., “Hear No Evil: The Acoustical Evidence in the Kennedy Assassination” November 17, 2001, Dallas, Texas)

[33] Myers, Op. cit., p.147, footnote 158

[34] Eleven feet in 1.5 seconds equates to 7.33 feet/sec (5.0 mph).

[35] Thomas places great importance on the apparent order in the data. But the BBN test only placed microphones along a portion of the known motorcade route through Dealey Plaza. No microphones were placed in any locations where it is known from photographic evidence that no motorcycles were present, such as on the grass between Elm and Main streets, the Elm Street sidewalk, Main Street, Commerce Street, under the Triple Underpass, etc. The failure to place microphones in these locations resulted in the BBN test having no “control” recording for comparison purposes. Likewise, BBN only fired weapons from suspected firing locations. No test shots were fired from locations where shots obviously had not been fired, again, resulting in no “control” recording for comparison purposes.

[36] Myers, Op. cit., pp.146-47

[37] Myers, Op. cit., p.49

[38] These errors in both text and graphics, as well as several other minor errors (See Errata below), have been corrected in the revised final report which is available for download HERE. None of these minor errors alter the conclusions.

[39] HSCA Report, page 81

[40] Myers, Op. cit., pp. 34, 64, 68, 108

[41] Myers, Op. cit., pp.90-95; 163-168

[42] Myers, Op. cit., pp.167-168


Errata

The following graphic and textual changes have been made to the June 1, 2007 edition of Epipolar Geometric Analysis of Amateur Films Related to Acoustics Evidence in the John F. Kennedy Assassination:

Exhibit 19. Distance traveled in 0.95 Seconds (not 0.9 seconds); 10.56 F/S between Z150-176 (not 11.87 F/S); 12.07 F/S between H631-Z150 (not 12.73 F/S)

Exhibit 66. Position of McLain at D456 to D496 shifts south 6 feet because of changes in alignment with Dallas County Courthouse from Dorman viewpoint. No changes in distance traveled or speed.

Exhibit 67. Position of McLain at D456/Z367 shifts south 6 feet; therefore distance traveled is 159.5 feet (not 165.5 feet); and projected speed is 13.49 F/S [9.2 mph] (not 13.96 F/S [9.5 mph]).

Exhibit 89. Line of sight between Dorman position and Dallas County Courthouse corrected. Text changes on p.126.

Exhibit 90. Correct match for Muchmore frame M427 is Dorman D111 (not D101). Caption change on p.128. Text changes at p.128

Exhibit 95. Position of Secret Service car at D191 and D196 shifts south 6 feet because of changes in alignment with Dallas County Courthouse from Dorman viewpoint. No changes in distance traveled or speed.

Timeline Chart (pages 2-3) Because of Exhibit 90 corrections, there is a related alteration to the Muchmore film timeline reflected on pages 2 and 3 of the timeline chart which now shows a 24 frame camera stop (not 13 frames) between Muchmore sequence 1 and 2, and a 330 frame camera stop between Muchmore sequence 2 and 3 (i.e., Muchmore sequence 2 synchronizes to a point 11 frames later than previously reported).