Question about Dr. Donald Thomas’s Dictabelt Offset Hypothesis

[Joe Elliott]

Oh my goodness, this is just ignorant. Partner, if you don't like being called out for ignorance, then you really need to stop posting until you know what in the world you're talking about.

Now, FYI, conspiracy theorists have written hundreds of pages on correlating the dictabelt gunshots with gunfire reactions in the Zapruder film. The HSCA discussed this very subject in its final report. Both of the expert consultant reports to the HSCA--the BBN report and the W&A report--discussed this issue; in fact, correlation with the Zapruder film was one of the criteria for identifying gunshot impulse patterns on the dictabelt, for crying out loud. How on earth can you not know this and yet pretend to credibly discuss the acoustical evidence?

Well, keep in mind that the alteration probably only removed 1-2 seconds' worth of frames from the shooting sequence in the Zapruder film. This would explain why the dictabelt gunshots do line up pretty well with the Zapruder film.

Joffrey, I recommend you get Dr. Thomas's book Hear No Evil. It includes four chapters on the acoustical evidence, totaling 131 pages, including an extensive discussion on the correlation between the dictabelt gunshot impulse patterns and the gunfire reactions in the Zapruder film. Dr. Thomas provides a very condensed version of this discussion in the following article:

https://www.maryferrell.org/pages/Essay_-_Acoustics_Overview_and_History_-_part_2.html

Why no, I don’t mind being called ignorant from someone who has been as evasive as you.


Question for Joffrey van de Wiel

Has Mr. Griffith answered your questions about the number of the “shots” on the Dictabelt recording?
And the timing of these “shots”?
And the source of each “shot” (TSBD, Grassy Knoll, etc.)?
And which Zapruder frame each “shot” corresponds to?

Have you found that there is the excellent correlation between the answers that Mr. Griffith has given you and the Zapruder film as he claims we can find?

Or have you found that Mr. Griffith has been evasive, as I predicted.

And if you haven’t found Mr. Griffith to be evasive, how many “gunshots” are to be found on the Dictabelt recording?


And Joffrey, if you have found Mr. Griffith to be evasive, don’t waste your time and money on Dr. Thomas’s “Hear No Evil”. You will find that Dr. Thomas does not answer these questions either, and is just as evasive as Mr. Griffith.

[Joe Elliott]

Well, keep in mind that the alteration probably only removed 1-2 seconds' worth of frames from the shooting sequence in the Zapruder film. This would explain why the dictabelt gunshots do line up pretty well with the Zapruder film.

Question:

Are you claiming that 1 to 2 seconds, or 18 to 36 frames, were removed from the Zapruder film?

Is so, what did they replace these missing frames with?

[Joe Elliott]

The failure of the acoustic analysis, is best shown by the failure to specify when the shots occurred relative to each other.

Back in January 1979, the acoustic experts published the intervals.

First shot at time 0.00 seconds, from the TSBD.
Second shot at time 1.57 seconds, from the TSBD.
Third shot at time 7.45 seconds, from the Grassy Knoll.
Fourth shot at time 7.91 seconds, from the TSBD.

These times are relative to the first shot. So, the 4 shots were over an interval of 7.91 seconds.

They have not published such a table since. Why?

Because the times don’t correlate to the Zapruder, Hughes and Nix films.

The Zapruder and Hughes film, while they don’t show when Officer McLain is at frame z223, they show him too far away to reach within 15 feet of Elm Street, where they need him to be where the acoustic data says he must be. Even if they choose the latest possible time, z223, it doesn’t work. A second difficulty is that if the first shot is at z223, the second shot is at z 252, too soon for the head shot, and the third shot is at z359, way too late to be the head shot.

Pushing the first shot back to z177 solves this problem, but it makes the McClain problem even more absurd, requiring him to travel 200 feet in one second. Impossible. And also, impossible, I might add, in 3.4 seconds.

The Nix film is a problem because it shows all four of the officers who are supposed to be right behind, the Presidential limousine at the time of the head shot, when one of them is supposed to be 120 to 160 feet behind. And the Hughes film shows Officers McLain and Baker right where they are supposed to be, 350 feet behind the Presidential limousine, between vehicles 10 and 11 (the Presidential limousine is vehicle 2) as late as Zapruder frame 160, still going at a slow steady speed. Both the Zapruder film and the Hughes film show the Vice-Presidential car just starting to turn onto Elm, establishing where Officer’s McLain and Baker are at Zapruder frame 160.

That’s it. They are all out of motorcycle officers who could be at Houston and Elm in time. No one is close to where the acoustic evidence says one motorcycle should be, 120 to 160 feet behind the President. Far from making an excellent prediction, the acoustic experts made about the worst prediction they could have made. Not 0 to 40 feet behind the President. Not 330 to 370 feet behind the President. But right in the black hole. Right where there are no police motorcycles with a radio transmitter.


Hence, for the last 40 years, no published list of the time intervals of the Dictabelt shots. An assurance that the time intervals match what is shown on the Zapruder film to an amazing degree, which is an amazing claim, considering that Mr. Griffith does not seem to know what these time intervals are. At least he is not telling us.

Dr. Thomas has since discovered a “fifth shot” somehow missed by the acoustic experts. I think the main value, is that maybe this fifth shot could partly fix the problem. Maybe it will allow a late first shot while still allowing a shot to occur at frame 313. But I don’t think so, because if it did, Dr. Thomas would publish the time intervals of the five shots and not keep them a secret.

Hence, the need to keep these time intervals between the shots a big mystery.

If this is not enough to convince people that the acoustic claims are bogus, I don’t know what is.


Now, expect Mr. Griffith to explain how ignorant I am and to post a link to a bunch of other materials, and to recommend a book or two for people to purchase, and to recommend of us to check it out. None of which will provide these time intervals between the acoustic “shots”.

[Jerry Organ]

From "The Acoustical Evidence in the Kennedy Assassination" by Dr. Donald B. Thomas (2001)

Table 1.- Synchronization of Putative Shots to Zapruder Frames

Acoustic Event		Tape Time		Tape-Time Interval		Real Time		Z-Frame Equivalent		Shot Origin
A		136.2		- 8.7		9.1		Z-147		No Match
B		137.7		- 7.2		7.5		Z-175		TSBD
C		139.2		- 5.6		5.8		Z-204		Rogue Shot
D		140.3		- 4.6		4.8		Z-224		TSBD
E		(145.1) 144.9		0		0		Z-312		KNOLL
F		145.6		+ 0.7		0.7		Z-326		TSBD

Tape Times from BBN Report Table 2.

Event E time correction at 8 HSCA 115.

Tape speed correction factor 1.043 [8 HSCA 27].

Zapruder Film speed 18.3 fps.

[Michael T. Griffith]

Table 1.- Synchronization of Putative Shots to Zapruder Frames

Acoustic Event		Tape Time		Tape-Time Interval		Real Time		Z-Frame Equivalent		Shot Origin
A		136.2		- 8.7		9.1		Z-147		No Match
B		137.7		- 7.2		7.5		Z-175		TSBD
C		139.2		- 5.6		5.8		Z-204		Rogue Shot
D		140.3		- 4.6		4.8		Z-224		TSBD
E		(145.1) 144.9		0		0		Z-312		KNOLL
F		145.6		+ 0.7		0.7		Z-326		TSBD

Regarding the 136.2/Z147 shot, keep in mind that the current version of the Zapruder film begins later than Zapruder said it began and later than Dan Rather said it began. There is a long gap between the first appearance of motorcycles on Elm Street and the limo's first appearance on the street. Researchers naturally suspect that a shot and reactions to that shot occurred in that interval, shortly after the limo turned onto Elm Street, and that that's why the segment was removed.

Before Zapruder knew what he was supposed to say, he told CBS News that he began filming as soon as the limousine turned onto Elm Street from Houston Street, as one would logically expect he would have done. But the current Zapruder film shows no turn onto Elm Street and skips from the motorcycles' first appearance on Elm Street to the limousine already on the street at Z133.

And before Dan Rather knew what he was supposed to say, he reported that the version of the Zapruder film that he watched the day after the assassination showed the limousine turning from Houston onto Elm: he said that in the film the limo "made a turn, a left turn, off Houston Street onto Elm Street."

Also, as Dr. Thomas documents, there is no acoustical or trajectory reason to label the 139.2 shot as a rogue shot. Blakey insisted on rejecting that shot because it meant two gunman were firing from behind.

[Joe Elliott]

Joe, it would be easier to follow your argument by using the actual material published by Dr. Thomas and object to what you believe is wrong. One source of "Hear No Evil" is here: http://www.whokilledjfk.net/hear_no_evil.htm

If you go to section FILMED EVIDENCE OF THE MOTORCYCLE you have a table of shots and Z-frames (Table 1). It says that "Tape Times from BBN Report Table 2.", which I haven't checked, but the times you're asking for should be there.

Edit: unfortunately the figures don't display in the url I listed above.

Thank you Otto. This information is most helpful. I’ll start another thread on it in a day or two. At a glance, I can see why Mr. Griffith was not giving us this information directly, even though, the initial impression, is that it matches up with the Zapruder film. But I will show that this is bogus.

[Joffrey van de Wiel]

This is the  dictabelt recording combined with the Zapruder film. In the first half, gunshot sounds have been inserted in those places where the dictabelt shows impulses that the experts said were gunshots. In the second half we can only hear the actual dictabelt recording. This video shows four shots, with the third one the headshot at frame 313. Is it accurate? 

[Jerry Organ]

Regarding the 136.2/Z147 shot, keep in mind that the current version of the Zapruder film begins later than Zapruder said it began and later than Dan Rather said it began. There is a long gap between the first appearance of motorcycles on Elm Street and the limo's first appearance on the street. Researchers naturally suspect that a shot and reactions to that shot occurred in that interval, shortly after the limo turned onto Elm Street, and that that's why the segment was removed.

Before Zapruder knew what he was supposed to say, he told CBS News that he began filming as soon as the limousine turned onto Elm Street from Houston Street, as one would logically expect he would have done. But the current Zapruder film shows no turn onto Elm Street and skips from the motorcycles' first appearance on Elm Street to the limousine already on the street at Z133.

And before Dan Rather knew what he was supposed to say, he reported that the version of the Zapruder film that he watched the day after the assassination showed the limousine turning from Houston onto Elm: he said that in the film the limo "made a turn, a left turn, off Houston Street onto Elm Street."

Also, as Dr. Thomas documents, there is no acoustical or trajectory reason to label the 139.2 shot as a rogue shot. Blakey insisted on rejecting that shot because it meant two gunman were firing from behind.

Seems to me that Zapruder and Rather were innocently volunteering context. They just meant the Presidential car was on Elm having come from Houston Street, as opposed to having come down the straight section of Elm Street. They didn't necessarily mean the Zapruder film originally included the turning of the car onto Elm.

Where Zapruder started filming the segment with the limousine was a reasonably optimal moment.



He had already seen how possibly slow and drawn-out the turn was and how far away was the subject.



If Zapruder had started filming when Tina Turner did, it would have added about eight seconds to the start of the film with the limousine in it. He had plenty of film time available in the camera.