The Kennedy Assassination Tapes
A Rebuttal to the Acoustical Evidence Theory
James C. Bowles


The Kennedy Assassination Tapes

A Rebuttal to the Acoustical Evidence Theory


James C. Bowles

Copyright © 1979 by James C. Bowles

(Reproduced by permission of the author.)

All rights reserved.

Posted for reference purposes only. No parts of this manuscript may be used or reproduced in any manner without written permission of the author, except in the case of brief quotations in critical articles or reviews, with the source properly cited.



The Select Committee on Assassinations was created in September, 1976 and terminated its activity in December, 1978. Its principal accomplishment, its so-called acoustical evidence, is at least inaccurate.

Briefly stated, the Select Committee on Assassinations received certain recordings considered to be recordings of the Dallas Police Department radio transmissions on radio channels 1 and 2 for Friday, November 22, 1963, covering the assassination of President John F. Kennedy and the wounding of Governor John Connally. The committee staff, in listening to the recording of Channel 1, more especially a five-plus minute period during the assassination when a microphone switch stuck in the "on" position resulting in an open transmitter, formulated a hypothesis: What if the radio with the open mike was in Dealey Plaza and recorded the assassination shots?

There was no reason to believe the open mike was in or even near Dealey Plaza, and more than ample reason to know that it was not. Nevertheless, the Committee staff pursued their hypothesis beyond ordinary means, resulting in what they declared to be acoustical evidence.

Through the process of developing and enhancing any notion which enhanced their hypothesis, and discounting or ignoring all challenges, the Committee staff concluded that there was ". . . a high probability that two gunmen fired at President John F. Kennedy." (Committee Report, page 93.)

The keystone to that statement is their Scientific Acoustical Evidence. If the acoustical evidence is true and correct -- if it exists, it leaves no doubt that, contrary to the Warren Commission Report, a fourth shot was fired at President Kennedy and that the shot came from a position referred to as "the grassy knoll," a shot fired by at least a second assassin. Further, that while two assassins do not establish a conspiracy, such an event is too coincidental to have occurred by mere chance.

However, should it be established that the open mike was not operating in a position from which it could have transmitted the sound of shots in Dealey Plaza, or should it be established that there are defects in the scientific deductions sufficient to nullify the authority of their scientific conclusions, that keystone would be removed and their acoustical evidence theory would collapse. With the loss of the acoustical evidence, Committee conclusions based on that evidence would suffer the same fate.

The absolute rebuttal of the "scientific acoustical evidence" is the objective of this Report.

More emphatically than the Committee concluded that their scientific acoustical evidence was valid, it is here and now unequivocally rebutted and rejected from its initial hypothesis to its final assumption.

An effort will be made to present rebuttal in terms which are easy to understand, but with sufficient detail to enable the reader to personally judge its validity.

The names of most officers have been deliberately omitted. Those officers who unfortunately had roles in the assassination scenario have been contacted at all hours and uncounted times by official investigators, private speculators and quacks. For those readers who choose to believe there was a conspiracy, the inclusion of names would not change their minds. Those who feel the matter is closed would not miss the names. And then there is that body of people in between who don't care one way or another.





November 22, 1963 started without any suggestion of its becoming a day of infamy. It was a cool and rainy morning, but as the day progressed, the weather improved. The clouds cleared, a warm sun shone brightly, and thousands of well-wishers turned out to welcome the President of the United States. The Dallas Police Department, in support of the Secret Service, began executing carefully planned arrangements for the President's visit. The dreary day became cheerful, and the President's motorcade was progressing exceedingly well. Years later it still seems paradoxical that such a fine day and a careful plan being executed so exactingly could have experienced such a tragic end. Actually, that day has never ended, nor is it likely that it ever will.

To refresh the reader's memory, Texas politics in that period could be described as "changing." The concept of Republican and Democrat was giving way to the ideology of Conservative and Liberal. Democrats in Texas were at odds with each other. The headlines of The Dallas Morning News, November 22, 1963, read, "Storm of Political Controversy Swirls Around Kennedy on Visit, " and "Split State Party Continues Feuds." In the 1960 election the Kennedy-Johnson ticket lost in Dallas while carrying Texas by an alarmingly small margin. Dallas had been described as a developing seat of conservative philosophy and Republican politics. President Kennedy had embarked on a tour of Texas in an effort to raise campaign funds and to unite party members. The President, accompanied by Vice-President Lyndon B. Johnson, Texas Governor John Connally, and an entourage of dignitaries, wives, staff members, and the media was in Dallas for a luncheon and speech at the Trade Mart, Stemmons Freeway and Industrial Boulevard. Some of the President's advisors were opposed to his appearance in Dallas, but he would not be dissuaded. Success in Dallas should be profitable, and rally the Democratic Party in Texas in support of his candidacy in 1964.

Plans for such a visit are lengthy and complex. The Secret Service is charged with the primary duty to protect the President. In that capacity, their representatives and Dallas Police executives were busily involved in developing plans a full week preceding the President's arrival. The Dallas Police Department furnished nearly 500 of its 1100 officers in support of those plans. Additionally, the Dallas County Sheriffs Department, the Texas Department of Public Safety, and the Dallas Police Reserves furnished nearly 100 more men. These were in addition to the local Secret Service and FBI personnel who were involved in the maximum effort to ensure the safety of the President. It was necessary to provide security for the arrival and departure area at Love Field, security along the 9 1/2 mile parade route, for the large gathering at the Trade Mart, and for the four-mile route back to Love Field. Obviously, the best of plans cannot recognize every contingency and respond successfully. There were numerous overpasses, uncounted manholes, storm sewers, trees, roofs and windows, and uncounted thousands of spectators who jammed the motorcade route.

The motorcade started a few minutes late but managed to proceed close to its schedule. The crowds were exuberant, encroaching on every vantage point along the route. Protestors were conspicuous by their absence. At Lemmon and Lomo Alto streets, a small girl held up a sign which asked the President to please stop and say hello, which he graciously did.

Incidents such as that, the clearing weather, the bright warm sun, and the tremendous and loudly cheering crowds were exactly what the president needed. He ordered the protective plastic bubble removed from his limousine. The Kennedy magic was at its best. Then, more than halfway along the route through Dallas, and just as the motorcade broke through the heaviest street crowds, with thousands more leaning and cheering from windows, the bottom fell out. Shots echoed through Dealey Plaza. President Kennedy was mortally wounded, Governor Connally was seriously wounded. The public was thrown into stunned disbelief. The local criminal justice community was thrust into momentary chaos, and the general reputation of the community was crucified.

Immediately after the assassination, the law enforcement community set into motion its investigation of the criminal offense. One person had been murdered and another wounded. Who had fired from what location, with what weapon? What was the motive? What was the ultimate objective? In addition there were the urgencies of national security and the succession to the presidency. President Johnson had to be securely guarded. Was there a conspiracy? What would happen next, how, where, by whom, and to whom? The follow-up investigation and results were prompt, suspicioned by some, and in some ways, inconclusive. However, based on the legitimate evidence, they were oomplete. Rumors and theories were plentiful, but facts were scarce. Essentially, the initial investigation led to the Texas School Book Depository, the last building along the motorcade route, providing an assassin a reasonably convenient access to the President. Inside the building an officer found the assassin's abandoned rifle. A name and description were developed, and a search was begun.

Exactly what transpired in the 400 block of East 10th Street in the Oak Cliff section of Dallas will never be known. According to witnesses, Officer J. D. Tippit stopped to talk to a subject later identified as Lee Harvey Oswald. Oswald spoke briefly with Tippit through the right front window of Officer Tippit's patrol car. Then, just after Tippit exited his car to approach Oswald, Oswald shot Tippit, killing him instantly. Fleeing on foot, Oswald was last seen running west along Jefferson Boulevard. Moments later officers following witness information were led to the Texas Theater. "Cry of Battle" and "War is Hell" were being screened. Officers entered the theater and observed Oswald sitting in the center section some three seats from the right-hand aisle and three or four rows from the rear of the auditorium. As Officer M. N. McDonald approached Oswald, Oswald stood, said "Well, it's all over now!", reached for a revolver he had concealed in his belt and attempted to shoot McDonald. Wedging the web-like skin between his thumb and index finger under the firing pin on Oswald's pistol, McDonald and other officers then subdued, disarmed and arrested Oswald. Witnesses to Tippit's murder identified Oswald as the assailant, and ballistics investigation, while not conclusive, strongly suggest that Oswald's revolver was the same weapon used to murder Officer Tippit. Unfortunately, Oswald would never stand trial for Tippit's murder. Eighty brief minutes in Dallas had set into motion unending episodes of concern, controversy, and intrigue.

One such episode prompted this undertaking. Congress gave life to the Congressional Select Committee on Assassinations, authorizing its probe into the assassinations of President John Fitzgerald Kennedy and Dr. Martin Luther King. Two years later and fifteen years after the assassination, the Committee concluded that there is a virtual certainty that President Kennedy was the victim of a conspiracy. They based the conclusion of their investigation on a recording of Dallas Police Department radio transmissions made during the motorcade which ended with the assassination. Their acoustics experts were satisfied that they had found not only the three generally acknowledged shots, but a fourth shot, recorded inaudibly where they had no reason to be found. Additionally, the acoustics experts concluded that the fourth shot was fired from a location generally referred to as "the grassy knoll," a mound some one hundred feet to the right front of President Kennedy's limousine. This would confirm the presence of at least a second assassin. The application of statistical theory would support the improbability that two such assassins, each acting without the knowledge of the other, would through coincidence alone select the exact same site and time for their acts. Accordingly, if there was a fourth shot and a second assassin, there would be reason to assume the existence of a conspiracy. However, no direct or corroborating evidence of a second shooter or a conspiracy was found.

The validity of the Committee findings depends entirely upon the validity of the acoustical studies and opinions. It is the intention of this author to prove that their conclusions are invalid. No criticism is directed toward the acoustics experts. Criticism would have to come from someone with greater scientific expertise, and would prove nothing.

I have neither evidence nor opinion with regard to how many assassins fired how many shots from what locations. As a trained and competent police officer, I remain open-minded in this area. Should competent evidence be uncovered, that investigation would be reopened. Until such evidence is uncovered, it would appear that the case should remain closed. What assassination investigators -- the amateur and the accomplished, the well-intentioned and the meddlers -- fail to consider is that the assassination of President Kennedy is a criminal act in the jurisdiction of the State of Texas, and in the venue of Dallas justice. For the Committee to declare that a second assassin fired from the grassy knoll is reckless and irresponsible. No competent attorney would go into a court with prosecution founded on such evidence. Why then would they offer such a concoction of wishful thinking as evidence?

Not having the time, the staff, and 5.8 million taxpayer dollars proved to be no handicap. The truth was before the investigators all the time. However, for reasons of their own, they chose to ignore the truth to pursue a fantastic hypothesis. The only problem is the necessity for some step-by-step preliminary explanations to facilitate an easier understanding of what really happened that tragic day in Dealey Plaza. The correct explanation is easy to make and to understand. After all, the truth always is its best defense.


A considerable number of references to exact times, even to tenths of seconds, exist in the Committee's Report and in the following chapters. Therefore, two things must be established here and remembered throughout:

1. How time was reported and recorded by Dallas Police dispatchers, and

2. An absolutely accurate time base does not exist.

Since an absolute time base does not exist, and since careful time margins are important, there should be an acceptable explanation as to how times are derived so the reader might form an individual opinion as to the accuracy.

First, consideration should focus on how the dispatcher's office operated with regard to determining and recording time, especially since the Committee Report did not mention their method for making such determinations, and since they reported the recording methods inaccurately.

A master clock on the telephone room wall was connected to the City Hall system. This clock reported "official" time. Within the dispatcher's office there were numerous other time giving and time recording devices, both in the telephone room and in the radio room. Telephone operators and radio operators were furnished "Simplex" clocks. Because the hands often worked loose, they indicated the incorrect time. However, their purpose was to stamp the time, day and date on incoming calls. While they were reliable at this, they were not synchronized as stated in the Committee report. Therefore, it was not uncommon for the time stamped on calls to be a minute to two ahead or behind the "official" time shown on the master clock. Accordingly, at "exactly" 10:10, various clocks could be stamping from 10:08 to 10:12, for example. When clocks were as much as a minute or so out of synchronization it was normal procedure to make the needed adjustments. During busy periods this was not readily done.

In addition to the times stamped on calls by telephone operators, the radio operators stamped the "time" as calls were dispatched, and the "time" that officers completed an assignment and returned to service. Radio operators were also furnished with 12-hour digital clocks to facilitate their time references when they were not using call sheets containing stamped time. These digital clocks were not synchronized with any time standard. Therefore, the time "actual" and time "broadcast" could easily be a minute or so apart.

Now, multiply this by two since the police department was operating on two radio frequencies. For convenience they were referred to as Channel 1 and Channel 2. Calls for police service or information as well as interdepartmental messages were placed through the police communications office. Telephone clerks trained for the task handled the initial contacts. Telephone calls which required that an officer be sent to render a service were transcribed by hand on "call sheets" to inform the radio dispatcher as to the location and nature of the service request. The telephone clerk inserted the call sheet into the nearest time clock, causing the call sheet to be stamped with a "call received" time. The operator then sent the call sheet to the dispatcher by way of a conveyer belt which passed continuously between operators sitting opposite each other at the telephone stations. The conveyer belt terminated at the radio operator's console. The radio operator, upon receiving a call sheet, would select the officer appropriate to handle the call, dispatch the call to that officer, and stamp the call sheet with a "call dispatched" time. When the officer assigned a call had rendered the necessary service, he would inform the dispatcher that he was "clear." The dispatcher would then stamp the call sheet to obtain a "call cleared" time, and inform the officer of his clearing time. On November 22, 1963, the regular business of the department was conducted on Channel 1, and radio traffic associated with the President's visit was conducted on Channel 2. Next, consideration should be given to the methods of individual radio operators. A given operator at a given time might broadcast "time" a little early in one event then a little late the next. Accordingly, a call initiated at, say, 10:10 might be stamped at 10:13 by the dispatcher, only to have intervening radio traffic delay his broadcast. He might go ahead and announce the dispatch time as 10:13 and the digital clock then showed 10:14. Time intervals of less than one minute were never used. Likewise, the time stated in periodic station identification time checks was not always exact. During quiet intervals, station time checks were usually on time. However, radio operators did not interrupt radio traffic in progress just to give a station check. Accordingly, an operator might give, say, the 10:30 check as 10:30 when it was actually 10:29 or perhaps 10:31 or later. On another occasion, that same operator might state, "10:31 KKB 364," the correct time even though he was at least a minute late.

In a later chapter more definition will be given to estimating time as exactly as possible under the circumstances. The reader may then decide whether those methods and assumptions are acceptable. For now, however, a brief statement with regard to "time" during the assassination period is as follows:

Channels 1 and 2 were in close synchronization, with Channel 2 announced time running approximately 15 seconds ahead of Channel 1. Accordingly, where a determination was necessary, a 15-second adjustment is used. Therefore, Channel 1 plus 15 seconds equals Channel 2 time: Channel 2 less 15 seconds equals Channel 1 time.

There is no way to connect "police time" with "real time." The Committee Report stated that the Dallas Police Communications system was recorded by continuously operating recorders. That statement is incorrect. Channel 1 was recorded on a Dictaphone A2TC, Model 5, belt or loop recorder. Channel 2 was recorded on a Gray "Audograph" flat disk recorder. Both were duplex units with one recording and one on standby for when the other unit contained a full recording. Both units were sound activated. It is important to note "sound" rather than "voice" because either sound or noise from any source, received through the transmission line, would activate the recorders. Once activated, the recorders remained "on" for the duration of the activating sound plus 4 seconds. The four second delay permitted brief pauses or answers to questions without the relay mechanism being overworked. On occasion, the recorders would operate almost continuously because rapid radio traffic kept them operating. On November 22, 1963, the Channel 1 recorders became, for practical purposes, continuous recorders for just over five minutes starting at approximately 12:29 pm (Channel 1 time) because the microphone on a police motorcycle stuck in the "on" position. The resulting continuous transmission kept the Channel 1 recorders operating for just over five minutes thus giving us a real-time recording for that period. The only problem was determining a basis for an accurate time reference during that period.

By noting the stated times and the duration of messages in the minutes preceding the incident of the open microphone, I have, for practical purposes, fixed the time for the start of the five-minute open mike episode at 12:29:10 p.m. (Channel 1 time). Time statements broadcast later confirm this as a rational assumption. (See PART II, CHAPTER FIVE for technical details demonstrating this confirmation.) Since it is important to have a zero-base from which one might project future time points, a decision was necessary. In using the start of the five-minute interval, and 12:29:10 (Channel 1) as the zero-base, with subsequent time factored thereon, "time" would at least be constant if not absolutely accurate. If not absolutely accurate, time statements cannot be more than a second or two off. The reader is encouraged to reach an independent decision based on the transcriptions of the radio transmissions contained in the Appendix.

It is, however, important to remember that

1. No exact record of "time" exists;

2. The several clocks were not synchronized;

3. The radio operators were not exact with regard to "time statements" on either radio;

4. The recordings were continuous only on Channel 1, and only while the mike was stuck open;

5. For an accurate, although derived, time reference point, 12:29:10 (Channel 1), the time the mike stuck open, will be developed and used in this text.


The Committee Report (Section B, page 79) stated that Dallas Police motorcycles were equipped with directional microphones. That statement is incorrect. The department only recently experimented with directional microphones. The motorcycles in 1963 were not so equipped. Being "omni" or non-directional, they would react to sound sources from many direction almost equally.

To the contrary of the Report, in 1963, the department used two types of microphones, carbon and dynamic. The radios then (and now) were limited to specifications authorized by the Federal Communications Commission. Police radio networks then (and now) were limited to frequency responses between 300 and 3000 hertz. While radio hardware has improved with technology, they are still limited to the 300 to 3000 hertz range. Microphones will not pick up with any better quality, nor will the telephone lines transport any better now than they did in 1963. To say they will is nonsense.

The radio network, broadcasting, receiving, and recording, involved only voice-grade circuitry. Microphones, carbon or dynamic, had an ordinary response of 300 to 3000 cycles. Sounds generated in the presence of a microphone which fell below 300 cycles or exceeded 3000 cycles were converted to a sound the system was capable of handling, provided the sound was sufficiently dynamic to be heard. In such cases it might be difficult to identify the specific sound or its source, but some sound would be present. Another consideration would be the condition of the microphone itself. Some were better than others while some were very well worn. A response of 300 to 3000 cycles would only be ordinary, not exact.

Next, the sound complex picked up was passed through the motorcycle's transmitter, and a signal was generated. This signal was picked up by anyone or a combination of remote relay transmitters situated at locations throughout the city. There is no record as to which relay transmitter or transmitters were being used during the assassination, so it can only be said that the signal was picked up by a remote transmitter. The signal was then converted to a telephonic signal and sent over a telephone company leased line to the police transmitter at Fair Park, southeast of the downtown area. Telephone lines normally operate between 200 and 2800 hertz with perhaps a 10% variation on a given line, these too being voice-grade circuits. At the Fair Park transmitter, the telephonic signal was transmitted as a radio signal from the main antenna to the mobile units throughout the city, and was sent by another leased telephone line through telephone company equipment to the police dispatcher's office downtown. In the dispatcher's office, the signal was split, one to the radio channel monitor or speaker; the other circuit was directed to the recorder. The sound level of radio signals activated a relay system and started the recorder to record the transmission. The recorder normally operated for the duration of a sound level in excess of that necessary to open the relay system, and for an additional four seconds thereafter.

The recorders were voice-grade units operating normally from 300 to 2500 hertz. Sound was not recorded by sharp needle cutting a sharp groove, but by a comparatively blunt needle which pressed a furrow in the thin plastic surface thereby creating a low fidelity recording. It should be noted that the Dictaphone equipment was designed only for that purpose, and it served that purpose well. It was never intended that it should make sophisticated recordings which could be replayed endlessly without loss in quality. It would be amazing and a credit to the Dictaphone equipment used had it served so profoundly as to record inaudible impression patterns picked up by a low quality microphone, passed through a low frequency transmitter, then through a voice-grade telephone line to a second transmitter, then a second telephone line, then to the recorder without even losing the N-waves which preceded the inaudible impression patterns calculated to be the assassin's gunshots. Fantastic!

Another characteristic of the recorders should be mentioned. On occasion, line noise would cause them to run but record no intelligible sound. On other occasions, parts of some messages might go unrecorded. For example, an officer might state that he was now in service, but the recorder would only record the dispatcher's acknowledgment. The Gray Audograph had another peculiarity. This was an old and much used unit. There was a sensitive worm-screw adjustment in the recording needle mechanism. When it didn't function exactly, it might omit some of one message only to repeat another message two, even three or more times. This occurred several times during the Channel 2 recordings of broadcasts during the assassination. Also, when the needle did not "groove" correctly a ghost signal might occur. Again, this was not the fault of the equipment. The unit was old and well worn.

A significant consideration for both recording units is that of recording and play-back speed. It was a common experience to observe noticeable changes in speeds between units. This becomes increasingly important when attempting to make critical time measurements. In fact, time measurements in the thousandths, even hundredths of a second are virtually impossible since the exact recording speeds are unknown and cannot be determined.

Further discussions of radios and recordings will accompany specific situations in later chapters. However, these explanations are important to the reader's future understanding.


Back to the top

Next Chapter . . .

Table of Contents


Search this site
    powered by FreeFind

Back to archive of acoustical evidence

Back to JFK reports and documents menu

Back to JFK menu

Dave Reitzes home page