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APPENDIX E SIREN SOUNDS
Pages 89-91

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From page 89... ... The complete absence of siren sounds for two minutes is difficult to explain on this scenario, and the sounds, when they do appear do not seem appropriate for a motorcycle in the motorcade, or even one catching up to the motorcade. If Officer McLain had the open microphone, it is particularly surprising that he picked up no siren sounds while accompanying the motorcade to the hospital but, at the same time, his microphone was so sensitive that it could pick up the Channel II cross talk from a nearby vehicle. Read the entire page →
From page 90... ... We might have been going as fast as 50 miles an hour I am sure...." If one assumes that on the streets and access ramps the average speed is 40 miles per hour, that the average acceleration in a turn is 0.2g, and that the Zapruder film gives the time to leave Dealey Plaza, the above 187 seconds would require an average speed on the Stemmons Freeway of 58.5 miles per hour, which seems reasonable in view of Agent Greer's testimony. It should be noted, however, that there is considerable uncertainty as to the speeds attained, the location of the open microphone, and the time following the assassination at which the "Go to the hospital" was broadcast. Read the entire page →
From page 91... ... Please APPENDIX E 91 "...hold everything..." identification with the known firm data, it should not be misinterpreted as a proof of this interpretation or as a reliable determination of the location of the vehicle with the open microphone, since there is considerable uncertainty as to speed of the vehicle. There is also contradictory evidence about the time interval between the assassination and the "Go to the hospital...." As this time is lengthened the average speed is reduced. Read the entire page →

From page 89...

... The complete absence of siren sounds for two minutes is difficult to explain on this scenario, and the sounds, when they do appear do not seem appropriate for a motorcycle in the motorcade, or even one catching up to the motorcade. If Officer McLain had the open microphone, it is particularly surprising that he picked up no siren sounds while accompanying the motorcade to the hospital but, at the same time, his microphone was so sensitive that it could pick up the Channel II cross talk from a nearby vehicle.

Read the entire page →

From page 90...

... We might have been going as fast as 50 miles an hour I am sure...." If one assumes that on the streets and access ramps the average speed is 40 miles per hour, that the average acceleration in a turn is 0.2g, and that the Zapruder film gives the time to leave Dealey Plaza, the above 187 seconds would require an average speed on the Stemmons Freeway of 58.5 miles per hour, which seems reasonable in view of Agent Greer's testimony. It should be noted, however, that there is considerable uncertainty as to the speeds attained, the location of the open microphone, and the time following the assassination at which the "Go to the hospital" was broadcast.

Read the entire page →

From page 91...

... Please APPENDIX E 91 "...hold everything..." identification with the known firm data, it should not be misinterpreted as a proof of this interpretation or as a reliable determination of the location of the vehicle with the open microphone, since there is considerable uncertainty as to speed of the vehicle. There is also contradictory evidence about the time interval between the assassination and the "Go to the hospital...." As this time is lengthened the average speed is reduced.

Read the entire page →

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APPENDIX E SIREN SOUNDS Pages 89-91

APPENDIX E SIREN SOUNDS
Pages 89-91