This summarizes an effort to find a first shot that missed timing estimate by using two different techniques, in succession, in order to reduce the variability in this estimate versus the variation seen within the general pool of testimonies. This consists of (1) Using “anchored” testimonies (sound with sight or photos) to reduce the variability within the testimonies that could be used to estimate the limo’s position at the timing of the first shot, and then augment that by (2) Using the power of averaging on those testimonies to help converge on a final estimate for the limo’s position at the time of a missed first shot. (In discussions here, the term witness testimony could include statements that may have been made with or without oath).
Background:
The wide variety of eyewitness testimony from Dealey Plaza seemingly has a large amount of variation regarding the timing of the first shot. Having testimony with a large variability makes it difficult to get an accurate estimate of the first shot timing, and has certainly contributed to the debate and lack of agreement on the first shot's timing over the years. This page describes a modified way that was tried in order to extract some insight into the first shot timing by using a subset of eyewitness testimony that I refer to here as "anchored testimony".
In some early personal experiences I have noticed that a memory which included two independent senses (e.g. sensing both an audio & visual reference stimuli at the same time) has made for more accurate and clearly recallable memories for me vs. other memories with just one of these senses associated with it.
Along these lines I decided to look at Dealey Plaza witness testimony that reported hearing at least 3 shots, but specifically regarding first shot the testimony had two distinct components, i.e. testimony based not only on hearing a first auditory shot sound but which was also augmented contemporaneously with a specific visual landmark memory location regarding the presidential limo. I will call these “anchored” testimonies where the time the sound was heard was also anchored with a point in space by a fixed visual location reference or landmark.
The subset of testimonies fitting this definition will be markedly smaller than the set of all the testimony that's out there, but by defining the sampling in this way, the aim was to get a subset of more accurate results. The goal was to define/refine the testimony criteria in a way which would not bias the testimony selection towards any specific location (avoid biasing the mean result, i.e. cherry picking bias). Invariably, like all testimony, there will still be some uncertainty in the exact timing and positions related to interpretation and application of such a subset of testimonies, but the expectation is the large variability found throughout the other non-anchored eyewitness testimony can at least be reduced in order to narrow down the data in order to get a clearer picture of the first shots occurrence in space-time.
If the auditory memory was associated with a photo view or camera reaction while watching the limo, that testimony was also considered as the photo could be used to establish approximate timing and/or visually anchored landmarks. Statements such as "the limo was nearby" or even "they were just in front of me" or "had just turned the corner and proceeded a little ways", without an additional landmark were considered a little too vague for this analysis, as location would depended on stance, angle of body turn, amount of head turn, even eye positioning and would have unclear or undefined distances, so these statements were not included here for landmark or photo anchoring.
The attachment link summarizes the results so far, and includes plotted estimates for line of sight to the presidential limo on a Dealey Plaza map for those individuals at the time of their first shot testimony. In one case, two options for an individual's testimony are evaluated, as there has been a lot of debate about that individual's original testimony. Looking at those two possibilities for what that one witness recalled also provides a good example on how variability in testimony interpretation can impact the overall average assessment of multiple testimonies, in this case specifically the average presidential limo position at the time of the first shot.
The work so far in the link below summarizes the tally of estimated presidential limo positions at the time of the first shot sound using anchored testimony including a fixed background landmark or photo view/camera reaction.
https://drive.google.com/open?id=1CG0uOpkq6IyKtjFGQvYoURKZnG0HBgq5
Interpreting eyewitness testimony of chaotic events will likely always be fraught with inherent challenges, but in the final map diagrams on the last page of the attached link, using this approach there seemed to be a location convergence starting to appear using the average of 6 estimated presidential limo positions mapped out around the time the first shot was heard. The average limo location appeared to be around a z133 timing position (if including the Willis slide #5) or alternately slightly before a z133 timing position, around ~z124, (if using the Willis #4 slide).