According to Josiah Thompson in Six Seconds in Dallas, (1976, p. 29) that out of 65 witnesses reporting:
40 said the second and third shots were bunched (closer together)
13 said three shots were evenly spaced
7 said first two shots were bunched
5 said four shots with first two bunched, a pause, then final two bunched
Various studies have been conducted since and despite some differences in interpretation of qualitative witness data, these findings remain basically identical. Then again, witnesses can be mistaken and there?s just too many psychophysical variables in play to conceivably account for, so this data can be used with extreme caution.
The bulk of the earwitnesses support the theory that the last two shots were closer together.
And the bulk of the eyewitnesses support the theory that the Presidential limousine stopped or almost stopped. Indeed, there is even stronger support from the witnesses for the limousine stopping then there is for the last two shots being bunched together.
And yet, we know from the Zapruder film that the limousine did not stop. It slowed from 13 mph to 8 mph. It always went faster than jogging speed. Just ask Clint Hill.
Had the Zapruder film recorded sound, we would likely know the bulk of the witnesses were wrong on the shot sequence as well.
What are the odds of 61.5 % or 79.4 % of the witnesses being wrong by sheer luck? Astronomical. Assuming witness errors are independent events. But if witness errors are systematic, it?s no wild fluke at all.
Which teaches us that treating this as a statistical problem or a problem in probability is a mistaken. Statistics and Probability can only be used for independent events.
What could cause systematic errors in the ?Limousine Speed? witnesses? Look at Don Roberdeau?s map of Dealey Plaza. A great number of the witnesses were close to the cars three or more cars behind the limousine. They had a good look at those cars but not the limousine at the time of the shots.
When the limousine slowed from 13 to 8 mph, each succeeding car had to slow more abruptly then the car in front of it (common in heavy traffic). So, the cars further back had to stop.
Rather than admit that they were not close enough to see history, it appears many witnesses guessed. The cars they could see easily had stopped. That means the limousine must have stopped as well.
What could cause systematic errors in the ?Shot Spacing? witnesses? The fact that a single shot can generate multiple noises, like ?Crack ? Thump?. Why would this be more common for the last shot? I don?t know. Maybe because that was the furthest shot and the sounds would be more noticeably separate. Maybe because it was only with the third fatal head shot that witnesses realized the President was shot and they remembered the details of that shot better than the others.
In any case, we should not trust witnesses. Not as individuals. Not as a group based on the idea ?Well, they couldn?t have all made the same mistake?. Addendum:
Of the 59 ?Speed of Limousine? witnesses:
52.9 % said the limousine stopped
2.9 % said the limousine stopped or almost stopped
23.5 % said the limousine almost stopped
14.7 % said the limousine slowed
5.9 % said the limousine maintained its speed
In other words:
79.4 % said the limousine stopped or almost stopped
Of the 65 ?Shot Sequence? witnesses (Josiah Thompson):
61.5 % said the second and third shots were bunched together
20.0 % said the shots were evenly spaced
10.8 % said the first and second shots were bunched together
7.7 % said there were two pairs of bunched shots
If 79.4 % of the witnesses can be wrong about the speed of the limousine, why can?t 61.5% of the witnesses by wrong about the spacing of the shots?