National Academies Press: OpenBook

Report of the Committee on Ballistic Acoustics (1982)

Chapter: APPENDIX C TIMING OF CHANNEL I AND II EVENTS

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Suggested Citation:"APPENDIX C TIMING OF CHANNEL I AND II EVENTS ." National Research Council. 1982. Report of the Committee on Ballistic Acoustics. Washington, DC: The National Academies Press. doi: 10.17226/10264.
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Suggested Citation:"APPENDIX C TIMING OF CHANNEL I AND II EVENTS ." National Research Council. 1982. Report of the Committee on Ballistic Acoustics. Washington, DC: The National Academies Press. doi: 10.17226/10264.
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Suggested Citation:"APPENDIX C TIMING OF CHANNEL I AND II EVENTS ." National Research Council. 1982. Report of the Committee on Ballistic Acoustics. Washington, DC: The National Academies Press. doi: 10.17226/10264.
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Page 62
Suggested Citation:"APPENDIX C TIMING OF CHANNEL I AND II EVENTS ." National Research Council. 1982. Report of the Committee on Ballistic Acoustics. Washington, DC: The National Academies Press. doi: 10.17226/10264.
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Page 63
Suggested Citation:"APPENDIX C TIMING OF CHANNEL I AND II EVENTS ." National Research Council. 1982. Report of the Committee on Ballistic Acoustics. Washington, DC: The National Academies Press. doi: 10.17226/10264.
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Page 64
Suggested Citation:"APPENDIX C TIMING OF CHANNEL I AND II EVENTS ." National Research Council. 1982. Report of the Committee on Ballistic Acoustics. Washington, DC: The National Academies Press. doi: 10.17226/10264.
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Page 65
Suggested Citation:"APPENDIX C TIMING OF CHANNEL I AND II EVENTS ." National Research Council. 1982. Report of the Committee on Ballistic Acoustics. Washington, DC: The National Academies Press. doi: 10.17226/10264.
×
Page 66
Suggested Citation:"APPENDIX C TIMING OF CHANNEL I AND II EVENTS ." National Research Council. 1982. Report of the Committee on Ballistic Acoustics. Washington, DC: The National Academies Press. doi: 10.17226/10264.
×
Page 67
Suggested Citation:"APPENDIX C TIMING OF CHANNEL I AND II EVENTS ." National Research Council. 1982. Report of the Committee on Ballistic Acoustics. Washington, DC: The National Academies Press. doi: 10.17226/10264.
×
Page 68
Suggested Citation:"APPENDIX C TIMING OF CHANNEL I AND II EVENTS ." National Research Council. 1982. Report of the Committee on Ballistic Acoustics. Washington, DC: The National Academies Press. doi: 10.17226/10264.
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Page 69
Suggested Citation:"APPENDIX C TIMING OF CHANNEL I AND II EVENTS ." National Research Council. 1982. Report of the Committee on Ballistic Acoustics. Washington, DC: The National Academies Press. doi: 10.17226/10264.
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Page 70
Suggested Citation:"APPENDIX C TIMING OF CHANNEL I AND II EVENTS ." National Research Council. 1982. Report of the Committee on Ballistic Acoustics. Washington, DC: The National Academies Press. doi: 10.17226/10264.
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Page 71
Suggested Citation:"APPENDIX C TIMING OF CHANNEL I AND II EVENTS ." National Research Council. 1982. Report of the Committee on Ballistic Acoustics. Washington, DC: The National Academies Press. doi: 10.17226/10264.
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Page 72
Suggested Citation:"APPENDIX C TIMING OF CHANNEL I AND II EVENTS ." National Research Council. 1982. Report of the Committee on Ballistic Acoustics. Washington, DC: The National Academies Press. doi: 10.17226/10264.
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Page 73
Suggested Citation:"APPENDIX C TIMING OF CHANNEL I AND II EVENTS ." National Research Council. 1982. Report of the Committee on Ballistic Acoustics. Washington, DC: The National Academies Press. doi: 10.17226/10264.
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Page 74
Suggested Citation:"APPENDIX C TIMING OF CHANNEL I AND II EVENTS ." National Research Council. 1982. Report of the Committee on Ballistic Acoustics. Washington, DC: The National Academies Press. doi: 10.17226/10264.
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Page 75
Suggested Citation:"APPENDIX C TIMING OF CHANNEL I AND II EVENTS ." National Research Council. 1982. Report of the Committee on Ballistic Acoustics. Washington, DC: The National Academies Press. doi: 10.17226/10264.
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Suggested Citation:"APPENDIX C TIMING OF CHANNEL I AND II EVENTS ." National Research Council. 1982. Report of the Committee on Ballistic Acoustics. Washington, DC: The National Academies Press. doi: 10.17226/10264.
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Page 77
Suggested Citation:"APPENDIX C TIMING OF CHANNEL I AND II EVENTS ." National Research Council. 1982. Report of the Committee on Ballistic Acoustics. Washington, DC: The National Academies Press. doi: 10.17226/10264.
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Page 78
Suggested Citation:"APPENDIX C TIMING OF CHANNEL I AND II EVENTS ." National Research Council. 1982. Report of the Committee on Ballistic Acoustics. Washington, DC: The National Academies Press. doi: 10.17226/10264.
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Suggested Citation:"APPENDIX C TIMING OF CHANNEL I AND II EVENTS ." National Research Council. 1982. Report of the Committee on Ballistic Acoustics. Washington, DC: The National Academies Press. doi: 10.17226/10264.
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Below is the uncorrected machine-read text of this chapter, intended to provide our own search engines and external engines with highly rich, chapter-representative searchable text of each book. Because it is UNCORRECTED material, please consider the following text as a useful but insufficient proxy for the authoritative book pages.

About this PDF file: This new digital representation of the original work has been recomposed from XML files created from the original paper book, not from the original typesetting files. Page breaks are true to the original; line lengths, word breaks, heading styles, and other typesetting-specific formatting, however, cannot be retained, and some typographic errors may have been accidentally inserted. Please APPENDIX C 60 APPENDIX C TIMING OF CHANNEL I AND II EVENTS This Appendix discusses the results of a study of the times of occurrence of certain key events on Channels I and II. The times were determined in two ways: 1) by listening to the Bowles tapes and by measuring the strip charts (in Figures C-1 and C-2) of the tape recording signal levels as a function of time; and 2) by listening to tape recordings made from the original Gray Audograph and Dictaphone records. C-1. ANALYSIS OF BOWLES TAPES The Channel II transmission “You want me...Stemmons”* that occurs about 200 seconds after the transmission by Chief Curry, “Go to the hospital,” is clearly audible and intelligible on Channel I. It provides a common reference point for synchronizing the Channel I and II tapes, and we can use it to determine whether the events on Channel I identified by BRSW/WA as shots occurred before or after Chief Curry broadcast his instructions “Go to the hospital.” If these events occurred after Chief Curry's instructions, they could not be the assassination shots, The transmission “hold everything...” on Channel I coincides in time with the last of the events BRSW/WA identified as shots. The strip chart timings provide evidence to support an explanation of how this transmission could have occurred at the same point in real time as the matching “hold everything...” transmission on Channel II. They depend only on whether or not the instructions “Go to the hospital” preceded the events identified by BRSW/WA as shots. Channel I Recording Measurement of the interval on Channel I between “You want me...Stemmons” and the conjectured shots is straightforward. The logging recorder (Dictaphone) ran continuously over the time of interest (even though it was sound-actuated), and the tape recording that we used for our measurements shows no evidence of skips, repeats, gaps, halts or similar artifacts that would affect the timing. Table C-1 gives the times of the transmissions of interest to us on Channel I. use the print version of this publication as the authoritative version for attribution. *A transcript of the relevant portions of both tapes appears at the end of this appendix (Tables C-2 and C-3). It was obtained from J.C.Bowles. The time used by Bowles is retained on the transcript even though it differs from the one favored by the Committee.

About this PDF file: This new digital representation of the original work has been recomposed from XML files created from the original paper book, not from the original typesetting files. Page breaks are true to the original; line lengths, word breaks, heading styles, and other typesetting-specific formatting, however, cannot be retained, and some typographic errors may have been accidentally inserted. Please APPENDIX C 61 Channel II Recording Measurement of the time intervals on Channel I between “Do you want me...Stemmons” and “Go to the hospital” is more difficult. The logging recorder (Gray Audograph) was sound-actuated and did not operate continuously. So the actual record is shorter than real time. There are repeats in the Bowles' tape recording that occurred when the Gray Audograph playback stylus jumped back to a previous groove in the record much as the stylus on a scratched phonograph record often does. The tape recordings made available to us initially were in two segments, with a break occurring between the two transmissions of interest. The first segment was recorded at a speed different from that of the second segment. All of these artifacts required compensation in order to obtain an accurate determination of the interval between the two transmissions. Compensation was done as follows: a. Gap Barger had access to an unbroken recording of the entire interval of interest from which he was able to show that a section of the original Channel II recording 0.4 seconds long had not been captured on the recordings we initially used. b. Speed Compensation The relative speed of the two segments of tape can be estimated from the sound spectrographs discussed in Appendix B. From this analysis we determined that times measured from the first segment of Channel II, which we designate Channel IIA, had to be multiplied by a factor of 1.06 to convert them to the time units of Channel IIB, the second tape recorder segment. Further, Barger and Weiss ascertained by an analysis of tones on Channel I and Channel IIB that these two tape recordings were made at essentially the same speed and that no correction was necessary to convert Channel IIB times to equivalent Channel I times. BRSW reported that the Channel I times had to be multiplied by a factor of 1.05 to convert them to “real” time. We have not made this additional correction but instead have expressed all of our results in equivalent Channel I tape recorder time units. Table C-1 shows the use the print version of this publication as the authoritative version for attribution.

About this PDF file: This new digital representation of the original work has been recomposed from XML files created from the original paper book, not from the original typesetting files. Page breaks are true to the original; line lengths, word breaks, heading styles, and other typesetting-specific formatting, however, cannot be retained, and some typographic errors may have been accidentally inserted. Please APPENDIX C 62 TABLE C-1 Time measurements using sound level recordings (seconds) Event Measured Time Intervals Cumulative Time Cumulative Time Silence Duration w/o Repeats (Speed Corrected) (Speed Corrected) Tape Chart CHANNEL 2 Go to hospital 0 0 0 0 Hold everything secure 60.2 60.2 63.8 3.7,3.6 repeat 1 (6.2) 12:32 31.6 85.6 90.7 3.8 repeat 3 (3.8) 5.2 repeat 5 (3.3) 4.8,5.3 Get'em out of way 70.2 148.7 157.6 Gap begins 2.3 151.0 160.1 Gap duration 0.4 5.6 15.2 2.8 154.2 162.9 repeat 6 (3.5) 12:34 15.1 165.8 174.5 You want...Stemmons 14.4 180.2 188.9 5.5 CHANNEL 1 Hold everything (“shot” 0. 0. 0. 3) Bell 7.3 7.3 You want...Stemmons 16.3 170.6 170.6 use the print version of this publication as the authoritative version for attribution.

About this PDF file: This new digital representation of the original work has been recomposed from XML files created from the original paper book, not from the original typesetting files. Page breaks are true to the original; line lengths, word breaks, heading styles, and other typesetting-specific formatting, however, cannot be retained, and some typographic errors may have been accidentally inserted. Please APPENDIX C 63 measured time intervals between key transmissions on Channel II and the cummulative time, measured from “hold everything” at which these transmissions occurred, corrected for the speed difference between Channel IIA and Channel IIB. c. Repeats Five repeats are evident from listening to the tape. All of these occurred in places where there were distinctive audible transmissions. As explained below, not all of these repeats actually increased the duration of the tape. In two cases the stylus apparently jumped backward to the previous track and started to repeat, but then jumped forward to the correct track before the recorder completed a single revolution. When this occurred, the duration of the tape would not have been lengthened relative to the duration of the original record. The strip charts of Figures C-1 and C-2 provide the detailed information from which we can determine whether the duration of each repeat was an integer multiple of the period of rotation of the record or not, and we used them to identify these two cases. The three repeats that can be unambiguously identified by listening and by examining the strip chart pattern are: Repeat 1 at 65 sec. 6.2 sec. added, 6.6 sec. corrected time Repeat 3 at 122 sec. 3.8 sec. added, 4.0 sec. corrected time Repeat 6 at 177 sec. 3.5 sec. added, 3.5 sec. corrected time The repeats are multiples of about 3.5 seconds (corrected time), which time can be taken as the period of rotation of the recorder (the angular velocity of the recording disk on the Gray Audograph is not constant). The strip charts also can be used to measure accurately the duration of the silences. We found one very long (7 second) silence, starting at 155 seconds that we believe was caused by a repeat during a portion of the tape in which there were no distinctive audible patterns. Therefore, we have: use the print version of this publication as the authoritative version for attribution.

About this PDF file: This new digital representation of the original work has been recomposed from XML files created from the original paper book, not from the original typesetting files. Page breaks are true to the original; line lengths, word breaks, heading styles, and other typesetting-specific formatting, however, cannot be retained, and some typographic errors may have been accidentally inserted. Please APPENDIX C 64 Repeat 5 at 158 sec. 3.3 sec. added, 3.5 sec. corrected time All of these repeats caused the Channel II times to be increased and the tape timings must be reduced to correct for them. This is done in Table C-1 in the columns labelled “Cumulative Time.” There are two other possible repeats, one at 96 seconds (repeat 2) and the other at 129 seconds (repeat 4). The first of these is not a repeat that caused the tape to be lengthened, since only a single word (notified) of a longer passage is repeated. The second, repeat 4, is less clear: Repeat 4 at 129 secs 2.3 secs added, 2.4 secs corrected time Note that this is not a multiple of 3.5 seconds. In the case of this repeat and repeat 2, the stylus apparently jumped back for a fraction of a revolution and then skipped forward to the correct track, thereby terminating the repeat. The fact that neither of these lasted a complete rotation means that there was not a spurious increase in the tape duration, and the timings should not be corrected. d. Silences We are told by James Bowles that the recorders had hold relays which kept them on for approximately 4 seconds after a transmission ended (the time between the end of a transmission and the recorder turnoff depends on sound intensity and is longer for very loud sounds). We do not know the threshold for this hold relay, but it is reasonable to assume that it was about 10 db below the peak signal voltage. If a silence is less than 4 seconds, the recorder would not stop and the recorder time would correspond approximately to real time. If a silence is longer than 4 seconds, the recorder would stop and there is no simple way of determining the duration of the pause that might have occurred before it restarted. Note that starting with “Go to the hospital” at zero seconds to silence A at 106 seconds, all silences are less than 4 seconds. The use the print version of this publication as the authoritative version for attribution.

About this PDF file: This new digital representation of the original work has been recomposed from XML files created from the original paper book, not from the original typesetting files. Page breaks are true to the original; line lengths, word breaks, heading styles, and other typesetting-specific formatting, however, cannot be retained, and some typographic errors may have been accidentally inserted. Please APPENDIX C 65 Channel II recorder must have run continuously during this interval. Starting at 106 seconds, we have a number of silences greater than 4.5 seconds during which the recorder could have paused. They are: Silence A at 106 sec., 4.9 sec. duration, 5.2 sec. corrected time Silence B at 132 sec., 4.5 sec. duration, 4.8 sec. corrected time Silence C at 145 sec., 5.0 sec. duration, 5.3 sec. corrected time Silence D at 162 sec., 5.5 sec. duration, 5.6 sec. corrected time Silence E at 189 sec., 5.5 sec. duration, 5.5 sec. corrected time This pattern of pauses means that, although the tape ran continuously for the first 106 seconds, during the second 100 seconds it apparently paused 5 times. During any of these pauses an indeterminate amount of time could have passed before the recorder restarted. If during these 5 pauses the recorder had stopped for a total of 46 seconds, the “hold everything...” transmissions on the two channels would have coincided with time. We have no data that would allow us to determine how long the recorder actually stopped. It does not seem unreasonable that there would have been 46 seconds that Channel II was not being used during the period that the motorcade was occupied with making the trip to Parkland Hospital at high speed. In Appendix D, definite evidence is given that the Channel II recorder made at least one stop of 2.9 seconds duration between “hold everything...” and “You want Stemmons.” Results From Table C-1 we see that: 1) On Channel I, “hold everything...” (which coincides in time with the last of the BBN “shots”) occurs 171 seconds before “you want me... Stemmons”. 2) On Channel II, “go to the hospital” occurred 189 seconds before “you want me... Stemmons”, and 64 seconds before “hold everything...” use the print version of this publication as the authoritative version for attribution.

About this PDF file: This new digital representation of the original work has been recomposed from XML files created from the original paper book, not from the original typesetting files. Page breaks are true to the original; line lengths, word breaks, heading styles, and other typesetting-specific formatting, however, cannot be retained, and some typographic errors may have been accidentally inserted. Please APPENDIX C 66 By this analysis, the last of the BRSW “shots” occurred at least 18 seconds after Chief Curry issued his instructions “Go to the hospital” and the events identified by BRSW/WA could not have been the shots of the assassination. Except for determining the correction factor for time measurements in Channel IIA, this result does not require that the two “hold everything...” transmissions be identical; it requires only that the two “You want me...Stemmons” transmissions be the same. Note further that this result is deterministic, not based on probabilistic arguments. If one includes the known 2.9 second stop of the Channel II recorder discussed above and in Appendix D, the last of the impulses attributed to shots occurred at least 20.9 seconds after “Go to the hospital.” For the two “hold eveything...” transmissions to coincide the recorder would have had to be inactive for 46 seconds, in which case the conjectured shots would have occurred at least 64 seconds after the chief's instructions, “Go to the hospital.” There were five places where the recorder could have stopped, during which the 46 seconds of inactive time could have accumulated. For the events identified as shots by BRSW/WA to have occurred before Chief Curry's instructions, “Go to the hospital,” at least 20.9 seconds would have to be deleted from Channel II, or added to Channel I. We see no evidence of anything that would allow us to shorten the Channel II times more than has already been done. Possible mechanisms that might permit us to lengthen Channel I are backward skips in the original Dictaphone recording of Channel I, or forward skips on playback. Backward skips on recording would require manual resetting of the recording stylus, an unlikely event given the automatic operation of the logging recorders, and would result in a superposition of recordings as discussed in Appendix D. Physical examination of the Dictabelt revealed no evidence of superposed recordings. use the print version of this publication as the authoritative version for attribution.

About this PDF file: This new digital representation of the original work has been recomposed from XML files created from the original paper book, not from the original typesetting files. Page breaks are true to the original; line lengths, word breaks, heading styles, and other typesetting-specific formatting, however, cannot be retained, and some typographic errors may have been accidentally inserted. Please APPENDIX C 67 C-2. ANALYSIS OF TAPES MADE DIRECTLY FROM ORIGINAL RECORDS After the preceding analysis of the Bowles tape recordings had been completed, the Committee obtained access to the original Gray Audograph and Dictaphone recordings from the Department of Justice. These were transcribed onto tapes carefully so as to keep the amount of 60 Hz hum and other artifacts added to the tapes to a minimum. Channel I Recording The Dictabelt (Channel I) was transcribed using a Dictaphone playback unit, with its playback speed adjusted to be equal to the original recording speed. The 60 Hz hum from the original record was used to make this adjustment. The Dictabelt was in poor condition and it was difficult to measure accurately the period of the 60 Hz hum required for the speed adjustment. No skips or repeats were apparent in the process of transcription, nor are there indications of any on the resulting tapes. The time between the “You want me...Stemmons” transmission and the “Hold everything...” transmission, which coincided with the part of the tape where BRSW/ WA said they found shots, was found to be 178 seconds. This compares with 171 seconds in the analysis of the Bowles tapes, in which we did not attempt to correct the times to real time. Channel II Recording The Gray Audograph disk (Channel II) could not be played on an original Gray playback unit without introducing skips and repeats. It was possible to play it successfully without either of these artifacts being introduced by using a phonograph turntable and phonograph arm, cartridge, and stylus. However, phonograph turntables operate at a constant rpm, whereas the Gray equipment maintains a constant linear velocity of the record relative to the stylus. Moreover, the Gray Audograph records from the inside out, whereas normal records begin at the outside. Thus, when the tapes are played back, there is a speed distortion that causes material at the beginning of the tape (the inside of the record) to be slowed down (time intervals between events are longer and the frequencies are lower than those originally recorded) and material at the end of the tape (end of the record) to be speeded up relative to true speed. use the print version of this publication as the authoritative version for attribution.

About this PDF file: This new digital representation of the original work has been recomposed from XML files created from the original paper book, not from the original typesetting files. Page breaks are true to the original; line lengths, word breaks, heading styles, and other typesetting-specific formatting, however, cannot be retained, and some typographic errors may have been accidentally inserted. Please APPENDIX C 68 We were able to use the 60 Hz hum present on the tape to correct for this speed distortion. The hum level on the original record was fairly high and is easily discernible in the tapes during the many intervals of relative silence. By measuring the period of the hum at different points on the tape, we can determine the correction factor that must be applied to time measurements to convert them to real time. The correction factor measurements for many points in the part of the tape of interest to us are plotted in Figure C-3. Note that in the interval between “Go to the hospital” at 22 seconds and “You want me... Stemmons” at 238 seconds the correction factor varies linearly with time. It has a value of about 0.95 at 130 seconds, the midpoint between these two events. We can relate the corrected (real) time, tc to the measured time, tm, by dtc=Kodtm+K'tmdtm where Ko is the time correction factor at the midpoint and K' is the slope of the correction factor line from Figure C-3. If the midpoint is taken as the time origin and this equation is integrated over the interval “Go” to “You,” we obtain Tc,You−Tc,Go=Ko(Tm,You−Tm,Go)+K'(T2m,You −T2m,Go)/2 where Ko=0.95 and K' the slope of the regression line in Figure C-3 is 0.0005. Since the T2m,Go=T2m,You, given that the time origin is midway between them, the second term on the right is zero, and Tc,You−Tc,go=0.95(Tm,You−Tm,Go). Substituting the values for Tm,You and Tm,Go, we find that Tc,You−Tc,Go=206 seconds. use the print version of this publication as the authoritative version for attribution.

About this PDF file: This new digital representation of the original work has been recomposed from XML files created from the original paper book, not from the original typesetting files. Page breaks are true to the original; line lengths, word breaks, heading styles, and other typesetting-specific formatting, however, cannot be retained, and some typographic errors may have been accidentally inserted. Please APPENDIX C 69 Results By this analysis Chief Curry instructed the motorcade to go to the hospital at least 206 seconds before the “You want me...Stemmons” transmission. The events identified by BRSW/WA as shots occurred 178 seconds before the “You want me...Stemmons” transmission, or at least 28 seconds after Chief Curry instructed the motorcade to “Go to the hospital.” This is a lower bound on the interval, because Channel II was sound-operated and halted when there were long periods of quiet. This second analysis confirms the findings from the Bowles tapes that the events identified by BRSW/WA as shots could not have been the assassination shots. If one includes the known 2.9 seecond stop of the Channel II recorder that is discussed in Appendix D, the impulses attributed to shots occurred at least 30.9 seconds aftr the instruction “Go to the hospital.” The two sets of measurements are in reasonable agreement. The two Channel I times, 171 and 178 seconds (original record), show that the Bowles tapes played back about 4% faster than real time. If we apply this same correction factor to the Channel II time obtained from the Bowles tape, we obtain 197 seconds as the estimate of the elapsed time between “Go to the hospital” and “You want me...Stemmons”. This compares with 206 seconds obtained from the tapes made directly from the original records. The difference, only 9 seconds, is probably due to the artifacts of the Bowles tapes: undetected skips, a sequence interpreted incorrectly as a repeat, or too low an estimate of the gap duration. We tried to be conservative in correcting for the artifacts on Channel II of the Bowles tapes and it is not surprising that the time interval between “Go” and “You” obtained from the Bowles tape is smaller than that obtained from the tape of the original recording. The tapes from the original records have fewer artifacts and a more certain history. They are believed to provide more accurate estimates of the time intervals than the Bowles tapes. use the print version of this publication as the authoritative version for attribution.

About this PDF file: This new digital representation of the original work has been recomposed from XML files created from the original paper book, not from the original typesetting files. Page breaks are true to the original; line lengths, word breaks, heading styles, and other typesetting-specific formatting, however, cannot be retained, and some typographic errors may have been accidentally inserted. Please use the print version of this publication as the authoritative version for attribution. APPENDIX C TABLE C-2 from J.C.Bowles ~12:30 to ~12:37 Channel I Transcript Bowles reports; the times and time intervals determined by the Committee are somewhat different). (Including changes suggested by Bowles in a letter dated December 30, 1981. The times indicated are those in 70

About this PDF file: This new digital representation of the original work has been recomposed from XML files created from the original paper book, not from the original typesetting files. Page breaks are true to the original; line lengths, word breaks, heading styles, and other typesetting-specific formatting, however, cannot be retained, and some typographic errors may have been accidentally inserted. Please APPENDIX C 71 Bowles' Times 12:29:20 ? ...Market Office... 12:29:27 ? ...All right... 12:31:00 (Motorcycle engine slowed down.) 12:31:02 ? I'll check it. (discounted by sound spectrograms) 12:31:10 (Motorcycle engine slowed to idle speed.) 12:31:12 “Hold everything secure...” (confirmed by sound spectrograms to be Sheriff Decker in a crossover from Channel II. 12:31:20 (Single tone of a bell.) 12:31:24 (Motorcycle engine at very slow idle.) 12:31:32 (“Bonk” sound-motorcycle engine revved up.) 12:31:40 (Motorcycle sound like it started moving.) 12:31:48 (Motor slowed down; perhaps another approached.) 12:31:52 ? ...on the phone. (Motor slow to idle.) 12:31:56 (someone whistling a tune in background.) 12:31:58 (“Bonk-Bonk” sound again.) 12:32:04 ? (Unreadable-sounds like...87...) 12:32:05 (Hetrodyne sound of Morse Code “V” and motor seems to speed up.) 12:32:08 603 603 out, Baylor. 12:32:22 36 36...(Motor slowed down just before “36”) 12:32:35 36 36...(Motor slow and irregular) 12:32:38 91 91 clear, request a “5”. 12:32:39 Dispatcher 531 testing, 1–2–3–4. 12:32:42 (Someone whistling again-unidentifiable tune.) 12:32:46 ? Loud and Clear. 12:32:48 48 48, lound and clear. use the print version of this publication as the authoritative version for attribution. 12:32:56 Dispatcher 56...(Motor revved up) 12:32:56 91 91... 12:33:00 (91) 91, request a “5”.

About this PDF file: This new digital representation of the original work has been recomposed from XML files created from the original paper book, not from the original typesetting files. Page breaks are true to the original; line lengths, word breaks, heading styles, and other typesetting-specific formatting, however, cannot be retained, and some typographic errors may have been accidentally inserted. Please APPENDIX C 72 12:33:01 (Blending with the ending of 91's message the sound of sirens can be heard, faintly but increasing in loudness.) 12:33:03 Dispatcher 10–4... Anybody know where 56 is? (sirens continue.) 12:33:08 ? He checked out on traffic 12:33:18 75 75, signal 5? (Sirens continue-motor slow and irregular.) 12:33:26 76 76 clear. (Sirens continue-motor revved up.) 12:33:34 (Sirens fade to inaudible.) 12:33:35 (Someone whistling again.) 12:33:38 (DSO?) Attention all units, all units... 12:33:50 ? (unreadable.) 12:33:52 191-Ch. II You want me to still hold this traffic on Stemmons until we find out something, or... 12:33:57 (103) clear. (Motor idling.) 12:33:59 Dispatcher Clear, 12:34. (Motorcycle engine revved up.) 12:34:00 76 76 clear. (Motor revved up.) 76 76 clear. 12:34:09 (12:34) Dispatcher 76 clear, 12:34. (Motorcycle sounds like it is moving.) 12:34:18 75 75 a “5”. (Motorcycle seems to gain speed.) 12:34:19 (Microphone closed .) 12:34:22 Dispatcher 24... 24 24...(unknown 3...) 12:34:25 Dispatcher Report to Inwood and Stemmons and cut all traffic for the ambulance going to Parkland. Code 3. use the print version of this publication as the authoritative version for attribution.

About this PDF file: This new digital representation of the original work has been recomposed from XML files created from the original paper book, not from the original typesetting files. Page breaks are true to the original; line lengths, word breaks, heading styles, and other typesetting-specific formatting, however, cannot be retained, and some typographic errors may have been accidentally inserted. Please APPENDIX C 73 12:34:30 ? (Unknown__seventy...) (Probably 75) 12:34:32 (24) Inwood and Stemmons? 12:34:35 Dispatcher Inwood and Stemmons where they come off Stemmons going to Parkland. 12:34:40 (24) 10–4. 12:34:43 Dispatcher Make your assignment Code, 3, 24. 12:34:45 (24) 10–4. 12:34:46 (12:35) Dispatcher 35 a signal 9 A at Lobello's, Ames and Northwest, 12:35. (Motorcycle transmitter stuck open again.) 12:34:52 Dispatcher Location, 93? ... Disregard...21... 21 21. 12:34:58 Dispatcher Code 3, Stemmons and Inwood, cut traffic. 21 10–4. 12:35:01 348/75 348...75... 12:35:03 Dispatcher 75 12:35:04 75 Signal 5? 12:35:05 Dispatcher 10–4. 12:35:06 65 65 clear, (heterodyne) 12:35:07 (12:36) Dispatcher 65 clear (4 interrupts), 12:36...4, did you call? (motor at slow idle.) 12:35:12 4 ...Cedar Springs and Mockingbird... (Noisy signal-unreadable...motor slow and irregular.) 12:35:22 Dispatcher 4, we have a mike butt stuck...bike... button stuck open. We can't hear snything. 4 (Still unreadable...motor slow and irregular.) 12:35:36 Dispatcher 93... 12:35:38 Ch. II Attention, all emergency equipment... (12:36) Dispatcher Attention, all emergency equipment... Do not use Industrial Blvd... Do not use Industrial Blvd., 12:36. (Motor slow, irregular) use the print version of this publication as the authoritative version for attribution. 12:35:47 93 93. (Motor idled down.) 12:35:48 Dispatcher Location? 12:35:49 93 Sylvian and Ft. Worth, (motor still slow.)

About this PDF file: This new digital representation of the original work has been recomposed from XML files created from the original paper book, not from the original typesetting files. Page breaks are true to the original; line lengths, word breaks, heading styles, and other typesetting-specific formatting, however, cannot be retained, and some typographic errors may have been accidentally inserted. Please APPENDIX C 74 12:35:54 (4)? El...uh...Eleven...(unreadable.) 12:35:57 260–Ch.II ...came from the 5th floor (Channel I dispatcher 24...) of the Texas Depository.. Bookstore...(sic) 12:36:04 (Transmitter closed with this message.) 12:36:05 Dispatcher 35, did you receive? 12:36:07 (35) I got it. 12:36:08 Dispatcher 10–4. 12:36:10 61 61 clear. 12:36:15 (12:37) Dispatcher 61 clear, 12:37. 12:36:21 4 4 to 11...1131... 12:36:26 21 21...(Siren slowing in background.) 12:36:28 Dispatcher 21...continue...(Interrupted...) 12:36:31 24 24... 12:36:35 93 93...(Dispatcher followed with:) use the print version of this publication as the authoritative version for attribution.

About this PDF file: This new digital representation of the original work has been recomposed from XML files created from the original paper book, not from the original typesetting files. Page breaks are true to the original; line lengths, word breaks, heading styles, and other typesetting-specific formatting, however, cannot be retained, and some typographic errors may have been accidentally inserted. Please use the print version of this publication as the authoritative version for attribution. APPENDIX C somewhat different). TABLE C-3 12:30 to 12:38 from J.C.Bowles Channel II Transcript (The times indicated are those in Bowles report. The times and time intervals determined by the Committee are 75

About this PDF file: This new digital representation of the original work has been recomposed from XML files created from the original paper book, not from the original typesetting files. Page breaks are true to the original; line lengths, word breaks, heading styles, and other typesetting-specific formatting, however, cannot be retained, and some typographic errors may have been accidentally inserted. Please APPENDIX C 76 BOWLES TIMES Approx. Dispatcher 12:30 KKB364. 12:31:16/17 125 to 250... 125 Approx. Dispatcher 15-2...(then, overriding the dispatcher...) 12:31:23 Channel II Go to the hospital...(“On our way”)..Parkland 12:31:08 Channel I Hospital. Have them stand by...... Get men on top of that there over...underpass. See what happenend up there. Go up to the overpass. (At least one transmitter was open for a while, now.) ? (Unreadable-sounds like “91 Champion.”) ? ...to 1... 1 Have Parkland stand by. Dallas 1 1...Dallasl... Dispatcher Go Ahead, Dallas.1. Dallas 1 Tell my men to empty the jail, and up on the railroad, uh, right-of-way there... I'm sure it's going to take some time for you to get your men in... Pull everyone of my men in there. Dispatcher Repeat, 1... I didn't quite understand all of it. Dallas 1 Have station 5 to move all men available out of my department, back into the railroad yards there in an effort to try to determine...just what and where it happenend down there, and hold everything secure until the homocide and other investigators can get there. use the print version of this publication as the authoritative version for attribution.

About this PDF file: This new digital representation of the original work has been recomposed from XML files created from the original paper book, not from the original typesetting files. Page breaks are true to the original; line lengths, word breaks, heading styles, and other typesetting-specific formatting, however, cannot be retained, and some typographic errors may have been accidentally inserted. Please APPENDIX C 77 Dispatcher 10–4, Dallas 1, Station 5 will be notified. 57 57... Dispatcher 1...... Any information whatsoever? 1 Looks like the president's been hit... Have Parkland stand by. 12:32 Dispatcher 10–4, Parkland has been notified, 12:32. 4 4... Dispatcher 4. 4 We have those canine units in that vicinity don't we? Dispatcher Stand by...1... 5 5 to 1... 1 (We're) headed for Parkland...(sirens loud in background) ? Is something the matter with Channel I? 5 5 to 1... 1 Go ahead. 5 You want... What disposition do you want to make on these men I have with me? 1 Just go on to Parkland Hospital with me. Just go on to Parkland. (Sirens loud in background) 5 10–4. Dispatcher 3... ? Dispatcher on numb...uh...on “1” seems to be..have his mike stuck...(loud sirens covered any remaining comment) ? (Unreadable-may be 20 or 220) (1) Get these trucks out of the way... Hold everything... Get 'em out of the way. Dispatcher 15–2... 15–2 15–2. Dispatcher There is a motorcycle officer up on Stemmons with his mike stuck open on Channel I. Could you use the print version of this publication as the authoritative version for attribution. send someone up there to tell him to shut it off?

About this PDF file: This new digital representation of the original work has been recomposed from XML files created from the original paper book, not from the original typesetting files. Page breaks are true to the original; line lengths, word breaks, heading styles, and other typesetting-specific formatting, however, cannot be retained, and some typographic errors may have been accidentally inserted. Please APPENDIX C 78 15–2 10–4. 12:34 Dispatcher 12:34. (190) I'm up on Stemmons. I'll check all these motorcycle radios. Dispatcher 10–4. 190 190... Dispatcher 190. Appx 190 12:33:52 You want me to still hold this traffic on Stemmons until we find out something, or let it go? Ch. I (Hetrodyne) (1) Keep everything out of this emergency entrance. 190 10–4. 136 136... Dispatcher 136. 136 A passer-by says—The Texas School Book Depository... stated the shots came from that building... (1) Get everything out of the way. (Referring to the vehicles clustering about the emergency dock.) Dispatcher 10–4. Get all that information, 136. 136 10–4. 12:35 Dispatcher 12:35. 142 142... Dispatcher 142. 142 142.. I talked to a guy up here at the scene of this...where the shots were fired at... and he said that he was sitting here close to it...and the very best he could tell, they came from this Texas Schoolbook De.. pository...Building here, with that Hertz Rental sign on top. use the print version of this publication as the authoritative version for attribution.

About this PDF file: This new digital representation of the original work has been recomposed from XML files created from the original paper book, not from the original typesetting files. Page breaks are true to the original; line lengths, word breaks, heading styles, and other typesetting-specific formatting, however, cannot be retained, and some typographic errors may have been accidentally inserted. Please APPENDIX C 79 12:35 Dispatcher 10–4. Get his name, address and phone number, and all the information that you can, 12:35. 15–2 15–2... Dispatcher 15–2. 15–2 (The) Captain advises, have all emergency traffic use some route besides Industrial... Have 283 cut the traffic at Hines and Industrial. Dispatcher 10–4...283, cut traffic, Hines and Industrial.. 283, cut traffic Hines and Industrial... (then, using simultaneous broadcasting:) 12:36 Attention all emergency equipment... Attention all emergency equioment.. Do not use Industrial Blvd... Do not use Industrial Blvd., 12:36. 260 260... Dispatcher 260. 260 I have a witness that says they came from fifth floor of the Texas..uh..Depository Bookstore (sic) at Houston and__Building. 12:36 Dispatcher 10–4, 12:36. 220 220... Dispatcher 220. 220 Where do you want traffic cut going into that area? Dispatcher Keep all traffic off of the emergency entrance to Parkland Hospital, and all emergency equipment off Industrial Blvd. 220 10–4. Dispatcher 1... (125) We have the emergency entrance secure at Parkland. 12:37 Dispatcher 10–4, 125, 12:37. 22 22... Dispatcher Go ahead. use the print version of this publication as the authoritative version for attribution.

About this PDF file: This new digital representation of the original work has been recomposed from XML files created from the original paper book, not from the original typesetting files. Page breaks are true to the original; line lengths, word breaks, heading styles, and other typesetting-specific formatting, however, cannot be retained, and some typographic errors may have been accidentally inserted. Please APPENDIX C 80 22 Get some men up here to cover this building... This Texas Schoolbook Depository. It is believed that these shots came from that... As you're facing it on, uh, it'll be Elm Street, looking toward the building, it would be your upper.. righthand corner...at the second window from the end. Dispatcher 10–4... How many do you have there? 22 I have one guy that was possibly hit by a ricochet, from a bullet off concrete, and another one that seen the president slump, and another one here that..that.. (137 covered 22 here)... 137 137... 12:38 Dispatcher 10–4, 12:38...137... 137 We have a man here that said he saw 'em pull a weapon back through the window off the second floor on the south...east corner of that Depository Building. use the print version of this publication as the authoritative version for attribution.

Next: APPENDIX D POSSIBILITY OF SUPERPOSED RECORDINGS »
Report of the Committee on Ballistic Acoustics Get This Book
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At the time of the assassination of President Kennedy, the Dallas police recorded sounds from an open microphone; these sounds have been previously analyzed by two research groups at the request of the House Select Committee on Assassinations. Both groups concluded with 95% probability that the recordings contained acoustic impulses which provide evidence for the existence of a shot from the grassy knoll area of Dealey Plaza. On the basis of these results and since shots definitely were fired from the Texas School Book Depository, the House Committee concluded that "scientific acoustical evidence establishes a high probability that two gunmen fired at President John F. Kennedy."

Report of the Committee on Ballistic Acoustics studied these reports and the Dallas Police recordings on which they are based. This book reviews the methodology employed in the evaluations of the recorded acoustic data and of the conclusions about the existence of a shot from the grassy knoll. According to this report, the acoustic analyses do not demonstrate that there was a grassy knoll shot, and in particular there is no acoustic basis for the claim of 95% probability of such a shot. The acoustic impulses attributed to gunshots were recorded about one minute after the President had been shot and the motorcade had been instructed to go to the hospital. Therefore, reliable acoustic data do not support a conclusion that there was a second gunman.

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