Dictabelt Acoustic Question – Who Rode the Motorcycle

[Joe Elliott]

Dictabelt Acoustic Question – Who Rode the Motorcycle

In the report of Bolt Beranek and Newman Inc., to the HSCA, by the acoustic experts James E. Barger, Scott P. Robinson, Edward C. Schmidt, and Jared J. Wolf, on January 1979, as seen below:

https://mcadams.posc.mu.edu/russ/jfkinfo/jfk8/sound1.htm

They claim that they can tell:

1.   The gunshots are recorded on the Dictabelt recording.
2.   They can tell when the shots occurred, relative to each other.
3.   They can tell the location of the rifle, either the TSBD or the Grassy Knoll.
4.   They can tell the location of the motorcycle officer who recorded the sounds of the gunshots.

We can’t check out Claims 1, 2 or 3, but we can check out Claim 4, which what this post will concentrate on. We will use their prediction on where the location of the motorcycle to be found to judge how much trust we can put into Claim 4, and in all their other claims as well.


Below are some statements they made in this report.

1.6 Findings

The results of our analysis of the tape-recorded evidence, together with the independent analysis of the echo-pattern match with the third (knoll) shot, permit the following findings:

1. The recorded sounds on Channel 1 of the Dallas Police radio dispatch system probably include the sounds of four gunshots fired in Dealey Plaza at about 12:30 pm on November 22, 1963.

2. The recorded gunshot sounds were sensed and transmitted by a police radio mounted on a motorcycle in the motorcade and positioned at distances ranging from 120 ft to 160 ft behind the Presidential limousine.

3. The first probable shot was fired at about 12:30:47 from the TSBD. The motorcycle position was then On Houston St. having only about 3 sec earlier slowed in preparation for the left turn onto Elm St. No shock wave indicating a supersonic projectile is seen as a precursor to the sounds of the muzzle blast, and none is expected, owing to the position of motorcycle with respect to the expected trajectory of the bullet. Therefore, no conclusion can be drawn about whether this first acoustic disturbance was due to a rifle orto a sound impulse as loud as the report of a rifle. However, the sound did originate in the vicinity of the sixth floor of the TSBD.

4. The second probable shot was fired about 1.6 sec after the first one(,) also from the TSBD. At this time the motorcycle was just at the corner of Houston and Elm. Again, no shock wave is seen as a precursor to the sounds of the muzzle, and, again, none is expected.

5. The third probable shot was fired about 7.6 sec* after the first one, and it was fired from behind the fence upon the "grassy knoll". At this time, the motorcycle was proceeding westward on Elm St. about 80 ft west of the intersection with Houston St. An apparent shock wave is seen as a precursor to the sounds of the muzzle blast. In as much as a supersonic projectile would show such a precursor when the motorcycle is in this position, the third shot is probably from a rifle.

6. The fourth probable shot was fired about 5.3 sec. after the TSBD. The motorcycle was on Elm St. about 90 ft west of the intersection with Houston St. An apparent shock wave is seen as a precursor to the sounds of the muzzle blast. Since the trajectory of the bullet would have been over the motorcycle, such a precursor would be expected for a rifle shot. Therefore, the fourth shot is probably from a rifle.

7. Additional police radio transmissions are intermittently probable shots. These transmissions contribute a few electrical impulse to the noise background in which the impulses of gunfire are set. However, these noise impulses are too few in number to have a material effect o n the accuracy by which the echo patterns of the acoustical reconstruction match the impulse patterns on the DPD tape.

Just a couple of quick comments:

6.   The fourth probable shot was fired about 5.3 sec. after the TSBD. The motorcycle was on Elm St. about 90 ft west of the intersection with Houston St. . . .

What the hell is this supposed to mean? 5.3 seconds after the first shot (Time 5.3 seconds) ? 5.3 seconds after the second shot (Time 6.9 seconds) ? Neither can be correct because the fourth shot should be the third shot. No, it seems to mean 5.3 seconds after the TSBD. Are they certain they don’t mean 5.3 seconds after the Washington Monument? Or maybe 5.3 seconds after the Eiffel Tower. What the hell does 5.3 seconds after the TSBD mean?

Well, if I assume a speed of about 11 MPH (the estimate they seem to go with), and the fourth shot was recorded 10 feet beyond the third shot, I guess this would be about 0.6 seconds after the third shot. So that would place the fourth shot around Time 8.2 seconds after the first shot. I think this puts it clearer than their phrase “5.3 seconds after the TSBD”.


So, they claim the location of the motorcycle which recorded the gunshot can be determined. It was 120 to 160 feet behind the Presidential limousine. And with my interpretation of what they were saying:

First shot, Time 0.0 seconds, from sixth floor or the TSBD. Motorcycle is approaching Elm Street, must be within about 12 feet of Elm Street (my estimate), if going 5 MPH around the sharp corner.
Second shot, Time 1.6 seconds, from sixth floor of the TSBD. Motorcycle was at the corner of Houston and Elm.
Third shot, Time 7.6 seconds, from Grassy Knoll. Motorcycle was 80 feet west of Houston and Elm.
Fourth shot, Time 8.2 seconds, from sixth floor of the TSBD. Motorcycle was about 90 feet west of Houston and Elm.

7. Additional police radio transmissions are intermittently probable shots. These transmissions contribute a few electrical impulse to the noise background in which the impulses of gunfire are set. However, these noise impulses are too few in number to have a material effect on the accuracy by which the echo patterns of the acoustical reconstruction match the impulse patterns on the DPD tape.

Just how many additional probable shots are they talking about here. It seems to be more than one. 5 more probable additions shots? 27 more probable additions shots? Exactly how many of these “N-waves” are on the recording? Do they occur throughout the 5-minute recordings? They seem to want to keep this information to themselves.


Well, back to my main point. What’s the problem here? The problem is that there is no police motorcycle anywhere near 120 to 160 feet behind the presidential limousine during the shooting.

http://mcadams.posc.mu.edu/russ../animation.htm

This animation shows the position of the cars, and the motorcycles, while in Dealey Plaza.

You can judge the accuracy of this animation from the Zapruder film and from the Robert Hughes film, of which a copy of it is here:

https://www.youtube.com/watch?v=Wwl2KmXUjcE

An addition good article on this subject is to be found at:

https://mcadams.posc.mu.edu/russ/sync.htm

There are four motorcycles right by the Presidential limousine. There are two more further back, Officers McLain and Baker. But these two don’t reach Main and Houston until around frame z160. They are still over 200 feet from Elm Street and the Presidential limousine is now over 130 feet up Elm Street. So, they are still in their usual position, about 330 feet behind the Presidential limousine. And the four motorcycles with the Presidential limousine are all within 20 feet of the limousine. So where the hell is this motorcycle that is suppose to be 120 to 160 feet behind the Presidential limousine?
 
The Hughes film cuts out about Zapruder frame 160, as Officer McLain and Baker are seen rounding the corner of Main and Houston. The acoustic experts placed the first shot around Zapruder frame 190. That gives less than 2 seconds to travel over 200 feet. But, at a speed of 11 mph, the motorcycles wouldn’t travel 200 feet, but more like 27 feet. I suspect they didn’t speed up to something like 90 mph to arrive in time at Elm Street to record the first shot.

So, it does not seem to be Officer McLain nor Baker. Back in 1996, Michael Griffith seemed to accept that Officer McLain could not have been the officer. So, he suggested an even more unlikely candidate, Officer Hargis. But he is even a less likely candidate.

http://michaelgriffith1.tripod.com/acoustics.htm

We can see Officer Hargis in the Zapruder film, right where he is supposed to be, right behind or even with the Presidential limousine. Far from being 120 to 160 feet behind the limousine, he was close enough to get blood and brain splattered upon him, as Mr. Griffith has pointed out many times.

The acoustic experts made a firm prediction on when the shots were fired. Where the shots were fired from. And where the motorcycle was that recorded the sounds of these shots. But the prediction of where the motorcycle would be found is totally false. 120 to 160 feet behind the Presidential limousine was about the worst possible estimate they could have come up with. They would have done better with 0 to 40 feet, or 300 to 340 feet

Well, they should have known. There is never a cop right when you need them. And not right when and where you need them, to salvage your theory.

If their judgment on where the motorcycle was so far off, how can be trust their judgment on where the shooters were? Or even if these are shots at all? And I certainly would have liked more clarification of these extra “probable additional shots” before judging whether these were shots are all.


So, who will step up to the challenge and answer these two questions:

Question 1:

What is the best estimate of when the first shot was fired?

This should be expressed as a Zapruder frame. Like Zapruder frame 152, or 190, or 222.


Question 2:

Which Motorcycle officer is the best candidate for being on Houston Street, within 15 feet of Elm Street, at the time of this first shot?



Then we will check out the various films to see how viable your theory is.

Or will all the CTers dodge questions 1 and 2? Stay tuned to find out.

[Dan O'meara]

Just to get the ball rolling:

1) First shot z223

2) McLain. In the animation you posted McLain is approximately 170 -180 ft away from limo (very rough straight line measurement using the scale provided)

[Joe Elliott]

Just to get the ball rolling:

1) First shot z223

2) McLain. In the animation you posted McLain is approximately 170 -180 ft away from limo (very rough straight line measurement using the scale provided)

Very good. You did not dodge either question. I wonder if Mr. Griffith will be able to step up to the challenge. Probably he’ll just give another tirade about how ignorant I am about the case and never get around to answering my two simple questions. Or make no response at all. He is the artful dodger.


Now. On your answers:

First Point:

It’s not enough to be within 170 to 180 feet. The acoustic expert said the motorcycle was within 120 to 160 feet.

Second Point:

Also, your cutting corners. Your measuring the distance across the grassy area. The 1978 acoustic expert said that not only was the motorcycle 120 to 160 feet from the limousine, but was within 15 feet of Elm Street.

Third Point:

By around z160, Officer McLain was slowly rounding the corner at Main and Houston, when the Hughes film stops. He has (roughly) 200 feet to go to get within 15 feet of Elm Street. He has 3.44 seconds to get there. This requires an average speed of 58 feet per second or 39 mph. And a considerable higher top speed to take into account acceleration and deceleration. So, I am to believe, that in the final 3 seconds or so, Officer McLain took off at “Ludicrous Speed”, just before the first shot was fired, when up to that point, he was being a good boy and rolling along at a steady 5 to 11 mph.

Fourth Point:

The acoustic experts, in their January 1979 report, do not clearly state when the fourth shot occurred. But they do state that the third shot was 7.6 seconds after the first. So, 7.6 seconds after Zapruder frame 223, we get to frame 362. So, we have no shot fired at all anywhere near Frame 312-313, but we have two shots at or after frame 362. Even with a silencer, our acoustic experts should still be able to detect the shockwave from the supersonic bullet at z312.


For these reasons I do not accept your z223/McLain scenario. But maybe others will disagree with me.


What must have been going inside the brain of Officer McLain, between z160 and z223, under the z223/McLain scenario (ala Inside Out):

[Dan O'meara]

To be honest Joe I know very little about this aspect of the case but something really sticks out to me that doesn't seem right. The majority of witness statements I've read describe 3 shots only and many describe a specific pattern - a shot, a pause, then two shots closer together. Not one statement I've read describes two shots in quick succession at the beginning of the shooting. The only way to kind of make it work is to ignore the first recorded 'shot'.

[Bill Chapman]

Darh Vader being a jerk

[Dan O'meara]

 

Not sure of the relevance but keep 'em coming!

[Joe Elliott]

To be honest Joe I know very little about this aspect of the case but something really sticks out to me that doesn't seem right. The majority of witness statements I've read describe 3 shots only and many describe a specific pattern - a shot, a pause, then two shots closer together. Not one statement I've read describes two shots in quick succession at the beginning of the shooting. The only way to kind of make it work is to ignore the first recorded 'shot'.

As a skeptic, I put minimum emphasis on eyewitness testimony.  I apply this not just to the JFK assassination case, but to the existence of UFO’s, Bigfoots, witchcraft, etc.

If one doesn’t do that, one can convince oneself of all sorts of nonsense. There is no way Bigfoot could remain hidden all these years, never getting killed by rifles, never getting run over by a car, or a logging truck. No one ever stumbling over a body. But, one can look at it that all these sightings, they can’t be all wrong, can they? The odds would be astronomical. No, they are not astronomical. Some people expect to see Bigfoot and some of them do see Bigfoot.

Or one could argue that the case that there were at least a few real witches in the sixteenth century. The number of eyewitness accounts, many recorded in court records, are huge. They can’t all be wrong. So maybe the burning of witches had some justification. No, it didn’t. There were no real witches.

The Dealey Plaza witnesses were distracted. They might ignore the first shot, thinking it was a motorcycle backfire, or a firecracker. They have been waited many minutes to see the President and First Lady pass by for a few seconds so they were not inclined to be distracted by other sounds.

And a single shot can product multiple sounds. A “crack” (from the supersonic bullet) followed immediately by a “thump”, from the muzzle blast. These two sounds would be most noticeable for the third shot, because it was the longest and the time between the “crack” and the “thump” would be the greatest. Also, for the third shot, there is the sound of the bullet striking the skull, the sound of a fragment hitting the windshield frame, the sound of a fragment hitting the windshield itself. Easy to mistake one shot for two.

And we are getting a little off topic, is there anyway a motorcycle could be at the location, very close to Houston and Elm, where the “HSCA Acoustic Hypothesis” requires it to be for this to be true?