Double Decker
by Stephan N. Barber


Double Decker

by Stephan N. Barber

24 June 1989

Copyright © 1989 by Stephan N. Barber

(Reproduced by permission of the author.)



After my first book was published, Steve Barber climbed all over me in his booklet, Double Decker, published by Robert Cutler. Barber's research paved the way for the NAS. I came to know and like Steve Barber, and my suspicion that he might have the key to one of the biggest puzzles in this case was worth a hearing, even if it disproved some of the very evidence that appeared to prove a conspiracy.(1)

. . . I was wrong on the position I took on the acoustics in my first book. I regret it.(2)

Harrison E. Livingstone, 1993



Double Decker by Stephan N. Barber


Thoughts on a chapter in High Treason that goes by the title, "Acoustics," and we use the quotation marks advisedly.




It's going to take a bit more than sarcasm printed in a book on the assassination of President Kennedy to convince me that the report by the National Academy of Sciences, NAS, is wrong about the Dallas Police Tape, DPT, recordings made XI/22/63, and whether or not there are shot-sounds on the original Channel One Dictabelt used by the Dallas Police Department, DPD.



I am deeply indebted to the following for their help, kindness and support:

Ned Reed - Chief, Shelby Fire Dept., Shelby, OH
Todd W. Vaughan - researcher, Jackson, MI
Bob Killen - Mansfield Dictaphone Company, Mansfield, OH
R. B. Cutler - assassinologist, Manchester, MA
R. E. Sprague - researcher, Arlington, VA
Paul Hoch - researcher, Berkeley, CA

Without all of you, I would never have been able to get my research into the hands of the National Academy of Sciences and perform subsequent studies of the Dallas Police Tape.




The authors, Bob Groden and Harry Livingstone, are claiming the "shots" are on the Dictabelt no matter what based on the assumption the Dictabelt is a copy and not the original. And, that the crosstalk segments, which disprove there are shot-sounds on the Dictabelt, are, and therefore were, superimposed. This says the "shots" are authentic and the crosstalk is not.

What possible reasoning would there be of editing in portions of Channel 2 transmissions onto Channel 1? To insert, and then take something out of the Dictabelt for no apparent reason is patently ridiculous. Did the people who supposedly performed this task have an insight that the tapes would be made available and distributed to the public? I find this doubtful; properties of the police department do not usually fall into the hands of the public. In fact -- tapes made from the Dictabelt were not made available by the Police Department, other than a copy provided to the National Archives -- which is now missing.

I refer the reader to pages 30 and 31 of the NAS report. There the reader can see that the NAS panel did not overlook the possibility of superimposed recordings. They did investigate it. Here in brief is what the report states:

The Committee studied seriously the possibility that the impulses analyzed by Bolt, Beranek and Newman, BB&N, and Weiss and Aschkenasy, W&A, were overlaid at a later time onto the "hold everything" message. Such over-recording could have occurred if the Dictabelt on the recording head was knocked backward by about one minute, in the first minute after the assassination, or if a new Dictabelt copy, made by audio-coupling while a Channel 2 recording was playing in the background, was substituted for the original. The Committee concluded this was not the case on the basis of:

(I) physical examination of the Dictabelt for indications of over-recording a substitution of a copy for the original;

(II) the unlikely nature of any of the highly contrived scenarios required to provide such an undetectable over-recording either accidentally or deliberately;

(III) the compatibility of the timing implied by the "hold everything" identification with other firmly established evidence, and

(IV) the conclusive acoustic evidence in the Dictabelt itself that the crosstalk recordings were made through a radio receiver with automatic gain control, AGC.

These different forms of evidence are all compatible with the recordings being made at the same time, and some are incompatible with the hypothesis of later superimposed recordings by audio or direct electrical coupling. Limitations of space dictate only the evidence of category (IV) will be reviewed here.

The digital analysis of the sound spectrogram can be used to demonstrate that the Channel 2 imprint on the Channel 1 recording was already present at the Channel 1 receiver and was not added later in the recorder or as an over-recording.

The by-radio nature of Channel 2 crosstalk is demonstrated by its detailed behavior in the presence of Channel 1 heterodynes (beep-tones) when another Channel 1 transmitter is keyed on with a more powerful carrier signal. The frequency offset between the two carriers gives rise to a heterodyne tone in the Channel 1 recording.

However, the Channel 1 receiver was fitted with AGC to hold the output level approximately constant; as a result the crosstalk signals decrease in intensity in a few tens of milliseconds, as does any residual transmission from the original open microphone. At the end of the Channel 1 heterodyne, the AGC gradually increases the receiver again, and signals in the open microphone transmission increase in intensity in the recording.

An excellent probing signal for the Channel 1 gain would be a Channel 2 steady tone acoustically coupled from the field loud-speaker to the open microphone transmitter. This would come in at a constant level and the variation in the level on the Channel 1 recorder should mimic the AGC action if the Channel 2 signals were present in this way.

Inspection of the digital spectrograms (and digital tabulations of the data) show that numerous Channel 2 brief-tones have a constant level from beginning to end. A crucial demonstration is provided by the Channel 1 heterodyne beginning at time 32.02 in one of the spectrograms. The underlying Channel 2 brief tone is substantially reduced in intensity at the beginning of the Channel 1 heterodyne and gradually grows back when the Channel 2 brief tone results after the Channel 1 heterodyne ceases. This behavior is validated by similar Channel 2 brief-tones underlying Channel 1 heterodyne signals in the "You want me to hold this traffic on Stemmons until we find out something ourselves" phrase and in a phrase, ". . . I'll check all these motorcycle radios," that is also present on both channels.

For the reasons discussed above and in its formal report, the Committee on Ballistic Acoustics, unanimously concluded that the acoustical impulses attributed to gunshots on the DPT were recorded about one minute after the President had been shot and the motorcade had been instructed to go to the hospital, and that reliable acoustical data do not support a conclusion that there was a "second gunman."

Here we have it in writing: the NAS panelists studied the Superimposition Theory and proved it to be impossible.



G. Robert Blakey, HSCA Chief Counsel, has been quoted as saying that he feels the recording needle on the dictaphone which recorded Channel 1 somehow "jumped back" and re-recorded over the already recorded gunshot-sounds, and that is how Sheriff Decker's voice overlaps the gunshot impulses. On page 81, Appendix D, the NAS report states:

. . . The tracks in the region of the "hold everything" expression were examined with particular care. The tracks were remarkably clear and parallel and showed no indications of superimposed recordings. . . .

According to my own investigation it seems impossible for the needle to have jumped back and re-recorded. My contact at the Dictaphone Company office in Mansfield, OH said:

. . . a widening of the grooves would occur if someone caused the needle to jump back . . . it would take "quite a thump" for the needle to jump back a full minute-plus after the assassination. . . .

NAS report further states,

. . . The suggestion the Dictabelt was jolted backward would've had to be knocked by just one minute of recording time. This . . . accident would have to occur in a manner to leave no acoustical widener, and in addition, someone irresponsible would have had to copy the Dictabelt, substitute the new Dictabelt with the old one, throw away the old one despite the importance of the case . . .

I find it difficult to believe that anyone would go to that much trouble: inserting Channel 2 transmissions to cover up something that wasn't there. And as for the needle "jumping back" (how about jumping forward?) and re-recording over the same section of the Dictabelt that contains the "shot-sounds," I feel strongly this theory is ridiculous and smacks of another attempt to keep the "shot-sounds" on the Dictabelt which recorded none.



High Treason maintains the photographic proves H. B. McLain had the open microphone that recorded the assassination's "shot-sounds" and the acoustical experts place the open mic 154 feet behind the presidential limousine. Allegedly McLain "admitted" he was about 150 feet behind the President when he was killed. High Treason does not examine the photographic evidence that shows McLain was not 150 feet behind the limousine at the time of the head shot.

The Robert Hughes film shows McLain completing his turn off Main onto Houston as the presidential limousine was completing its turn off Houston onto Elm. That places him a good 200 feet behind the limousine about ten seconds before the last shot was fired. The following information is from A Rebuttal to the Acoustical Evidence, an unpublished manuscript by J. C. Bowles.

McLain states that he was looking through the concrete peri-style bordering Houston Street when he saw Secret Service Agent Clint Hill running along behind the limousine, holding onto the hand rail on the trunk and then jumping onto the rear of the car. McLain was on Houston Street not Elm when the last shot was fired. See next page: Figure 1.

McLain further states that just after noticing Hill's action he received Chief Curry's order to go to Parkland Hospital, Code 3 (using red lights and siren). He said:

. . . I pulled up to Houston and Elm and turned left to go west on Elm. . . . I accelerated to catch up with . . . the motorcade. Turning right and up onto Stemmons Freeway, northbound, I opened it up. . . . I never left Houston Street until after the chief said for us to go to the hospital and for someone to check the overpass. The agent (Hill) didn't get onto the back of the limousine until some seconds after the last shot. I saw that happen while I was still on Houston Street, so while I only heard one shot, I could not have been on Elm Street until after the shots had been fired. . . .

Here we have McLain in his own words stating where he was when the shooting took place. It seems obvious why McLain never heard the DPT open mic sequence before his HSCA testimony. After hearing it, he stated on Dallas TV news (I have a video) that he was not the open mic culprit.

He said he turned his siren "on" after Chief Curry ordered him to Parkland. Many attempts have been made to say that because other officers near McLain had their sirens "on," he may have felt it was unnecessary for him to do the same. Oh?

High Treason relies on the statement of retired DPD officer Earl V. Brown to fit the open-mic motorcycle engine's sounds to those on the Dictabelt recording, the DPT. Brown told the Dallas Morning News that he saw the motorcade stop for about 30 seconds along the ramp leading onto the Stemmons Freeway.

On the DPT the motorcycle is running at a low speed during the "shot-sounds" and crosstalk. Then it accelerates, then decelerates, shifts gears, and accelerates again. For about 15 seconds it travels at a constant rate of speed, then decelerates once again and finally stops. It idles for about 20 seconds, then accelerates again! Only to go through a series of accelerations and decelerations throughout the next two minutes. By the time we first hear the sirens on the recording -- some two minutes AFTER the supposed gunshot-sounds -- the motorcycle is once again traveling slowly -- almost at an idle.

That does not sound like an officer traveling with the motorcade. This is borne out by my discovery of two other talk sequences during this open-mic part of the DPT.

The first is inaudible, an officer -- or someone -- saying, "What'd they do?" or "Who'd they shoot?" This occurs about 16 seconds after the erroneously named "carillon-bell" sound. The second is completely unintelligible and occurs about 20 seconds after the "V-for-Victory" beep-tones. Could these possibly be officers conversing back and forth?

H. B. McLain's actions do not coincide with the sounds recorded on the Dictabelt; his eyewitnessing does coincide with actions known to be well after the final shot. H. B. McLain's mic was not the open mic which recorded the DPT.



High Treason has the NAS taking three years to complete its report. The NAS scientists began about November of 1980 and their report was released May 14, 1982. 18 months is scarcely 36.

High Treason flatly states that some of Channel 1 is missing, and because some of Channel 2 is on Channel 1 "it (Channel 1) can't be the original."

WHAT?! The Channel 2 that is on Channel 1 is what this is all about: CROSSTALK. It's a very common occurrence. Let me show you other crosstalk I discovered which the NAS scientists missed. I sent it to them after their report was published. It occurred 15 minutes before the assassination, at 12:16/17 on Channel 1. There is no motorcycle engine sound drowning out or making it difficult to hear the crosstalk from Channel 2.


#72 Check 3 the first will be (deleted) Pride, colored male, 21 (deleted) Pride, he's a colored male, 23, and a (deleted) Pride, P-R-I-D-E, a colored make, 24.
Dispatcher Stand by . . . it's not registered to any of those.
#72 All right.

In the background, directly from Channel 2, at the same time #72 is speaking, can be heard:

#134 For your information you have cars lined up on Stemmons on the shoulder on both sides of Commerce Street north to Oak Law, it looks like . . . (Pause.)
#1& 131 turn on your red lights (Chief Curry to Motorcycle Officer B. J. Martin, riding left-outside flanker beside the Queen Mary, the Secret Service car behind the presidential limousine).


This is crosstalk, not an uncommon occurrence that afternoon. Strange, but the broadcasts coming from Channel 2 (in the background) through an open mic on Channel 1 are actually much clearer and crisper than they are on the Channel 2 recording. This can only mean one thing: the original broadcasts are much clearer during the actual time the officer is speaking on Channel 2 than the recording by the Channel 2 equipment.

Listening to a tape made directly from the original Channel 2 Gray Audograph disk, of which I have a second generation copy, many of the transmissions are distorted and fuzzy. All of the crosstalk is very clear -- clearer than it is on Channel 2 where it actually originated.

What this means is only the recordings made that day, 22 November 1963, are distorted. The actual transmissions were not distorted at the moment they were made over the police radio.

This is 100% proof of the crosstalk being authentic. Had it been edited in later from recordings of Channel 2 it would have been distorted and fuzzy. No crosstalk is; High Treason is, if you'll allow one aside, please.



There are those who say there are other ways in which Decker's voice could be overlapping the "shot-sounds" on the Dictabelt.

One such way: Decker may have been speaking in the background of Channel 1 while Chief Curry, riding in the same car, switched from Channel 2 to Channel 1 and caught Decker saying, ". . . hold everything secure . . ."

Why would Curry switch to Channel 1? Furthermore, the voice print of Channel 1's ". . . hold everything secure . . ." is identical to the voice print of Channel 2's ". . . hold everything secure . . ."

This kind of fingerprinting is irrefutable. Jim Bowles, now Dallas County Sheriff, insisting because he knew Decker for years, does not think it is Decker's voice on Channel 1. That may well be but NAS proved whoever spoke the phrase on Channel 1 is heard on Channel 2 also: Double Decker, but perhaps not to Bowles.

High Treason has Dr. Barger of BB&N telling the authors on January 23, 1981, "I don't agree with them (NAS) and I'm sure lots of others won't either." NAS was hardly into its study at that time; it is up to Barger to publicly refute the NAS report.

High Treason also suggests that some of Channel 1 was removed concerning a second gunman.

This is ridiculous. If this were the case, then why didn't the "plotters" also remove Chief Curry's and Sheriff Decker's orders to ". . . go to the railroad yards . . ." and ". . . go up to that overpass . . ." from the Channel 2 recording as well?

If all evidence was "covered up" concerning a gunman in any location other than the TSBD, this would have been the first to go, in that it points to a location other than the TSBD.



1) Both NAS and HSCA/BB&N/W&A are government sponsored; nothing is to be gained by insinuation.

2) H. B. McLain's mic was not the one responsible for the recording now known as the DPT.

3) The Dictabelt recording used in the NAS study was the original.

4) Crosstalk at the very time of the alleged "shot-sounds" is the clearest indication there are no such impulses on the DPT, therefore there is no acoustical evidence of the assassination of the President in Dealey Plaza.


In J. C. Bowles's unpublished manuscript, The Kennedy Assassination Tapes, several motorcycle officers state that a fellow officer had mentioned to them that his microphone had stuck open and that he had said "something he shouldn't have." The author refuses to name that officer, primarily on the grounds of ill health.

There is no reason under the sun for anyone in the best of health or not to be protected from the enjoyment of the truth. HSCA's acoustical analysis has been a fiasco from its inception. It has accomplished nothing but postponement of the inevitable. If there is a way of eliminating this total waste of time, energy and money, let's have it, so we can get on with finding, not who fouled up HSCA (most of us know that one) but who killed JFK.

1. Harrison Edward Livingstone, Killing the Truth (New York: Carroll & Graf, 1993), p. 346.

2. Harrison Edward Livingstone, Killing the Truth (New York: Carroll & Graf, 1993), p. 343.