* Based on a perception time study evaluating early voluntary reactions seen in and near the presidential limo on the Zapruder Film.
www.acsr.org/wp-content/uploads/2020/08/2020-Estimating-Occult-Timing-of-Surprise-Gunshot-Sounds-in-Silent-Film-via-Observed-Start-of-Human-Voluntary-Reactions-of-Concern-Roselle.pdf
As a follow up to the results of a Perception Time (PT) analysis which estimated the first shot timing in the JFK case, five additional studies are summarized here in light of that new perception time analysis which determined the first shot fired at JFK in Dealey Plaza was triggered about ½ second before z133.
The new PT analysis determined that the first shot in the JFK assassination shooting sequence was triggered at about zeq124 (an equivalent Zapruder frame which would be about half a second before z133 if the camera had been running continuously before z133). Here, five different other evaluations are looked at as If/Then checks to evaluate the consistency of these five other evidentiary data sets relative to the PT study's first shot timing determination.
1) If a first shot from the TSBD was fired at about ½ second before z133, Then given the unexpected loud discharge in close proximity to Elsie Dorman at that time it likely would have had some startling effect on her and her filming, as she was the closest person to the sniper nest actively filming at that time.
Results:
Dorman’s camera motions do appear to contain startle reactions consistent with a loud rifle report happening at the predicted timing for the first shot.
https://sites.google.com/view/dorman-zapruder-sync-on-elm-st/home
2) If the first shot was about ½ second before z133, Then in this timeframe Governor Connally’s initial voluntary left head turn start of reactions to it, at around z150, should align well in an overall shot timing analysis based on expected population voluntary perception times, and align as well or better than using his subsequent right head turn as the start of voluntary reactions around z162 (again both of these were voluntary, and not startle, reactions). For internal use in the calculations however, the same standardized time estimate for Zapruder's apparent involuntary startle reaction time is used with all three shots, as estimated from camera jiggle on the Z-film from shots 2 and 3.
Results:
A shot timing analysis utilizing Zapruder's estimated startle reaction time, and associated film jiggles for the shots, does support the new study's conclusion of the first shot taken half a second before z133.
An Excel program shot timing analysis was constructed based on the scenario of 3 TSBD shots, and adjusting associated inputs in order to standardize to a 0.21 sec Zapruder startle reaction time (as an estimated repeatable startle time for Zapruder) for all 3 shot sounds causing associated camera jiggle motions.
The shot timing estimate that appears to work best for the first shot in Connally's situation (when looking at his surprise voluntary perception times) is the shot timing scenario of half a second before z133. This is seen when one compares values for Connally's calculated perception time after the first shot, along with observations on the Zapruder film that Connally appears to have reacted slightly later vs all other presidential limo occupants in the film at that time. Connally did comment that he had time to think and time to react after hearing the first shot (perhaps taking a slight bit more time to process/recognize the sound as a rifle shot before reacting).
https://drive.google.com/file/d/1IDl5ladjJ-xFEOZ31vtPx5H5s1d32Nzn/view
In this first shot timing analysis, about 0.24 seconds after the first shot is triggered, the muzzle blast from it would arrive at Zapruder. With a slight startle and using a 0.21 second estimate for Zapruder’s startle reaction time, he conceivably could have a camera movement reaction starting around 0.45 seconds (0.24+0.21) after the shot triggered. This would equate to happening at frame z133. The interesting possibility that arises is that Zapruder’s reaction to hearing the unexpected first shot muzzle blast may have included some hand motion helping to facilitate restarting the camera when he did, at z133.
3) If the first shot was at about ½ second before z133, Then the Z-film blur around z157 (or any blurs between z135 and z226 for that matter) should not be the result of a first gunshot jiggle.
Results:
Extended jiggle analysis between z135 and z226 does not support a first shot happening in that timeframe.
https://sites.google.com/view/extended-jiggle-analysis/home
4) If the first shot was at about ½ second before z133, Then there should be at least some subset of the wide array of various first shot testimonies that would align with it.
Results:
A subset of testimonies, which would be expected to have lower than average variability for first shot timing estimates by virtue of having additional spatial anchoring, does appear to support the perception time study results as well.
https://sites.google.com/view/anchored-first-shot-testimony/home
5) Although the Tague curb incident doesn't define the exact first shot timing, we can look to see if there could be any consistency with that event and the third shot.
If the first shot was as early as ½ second before z133, Then it might be more unlikely the Tague incident was related to a missed first shot at that early point as there was nothing between the rifle and limo at that point, and even if there was some kind of deflection the bullet/fragment would have to deflect a lot, disfiguring it significantly, and still make it quite a long way down the Plaza. As such, a closer look at a scenario of a missing large fragment from the third shot at z313 escaping the limo might suggest that missing fragment as a possible and more likely explanation for the Tague curb mark (if the mark was indeed related to the shooting that day).
Results:
Modeling such a missing z313 fragment is difficult because of the uncertainty in some of the variable values. However using some reasonable best estimates for the key variables, a third shot fragment scenario appeared to be a distinct possibility for the curb strike (the modeled dynamics did not show it as being impossible) especially if a missing large bullet fragment escaping the limo had a reasonably high exit velocity needed to overcome the drag effects from the headwind/air along with a poor fragment ballistic coefficient.
https://drive.google.com/file/d/1CcnCy17Hwqqw3zBCK7ls8peA3DxmVzhk/view?usp=sharing
Overall conclusion: All 5 additional reviews based on other independent variables and data agree with and/or are supportive of the Perception Time study's conclusion for the early timing of the first shot.