Mark Tyler

The dictabelt is very important evidence in this case and should be studied and explained, whichever side of the debate somebody is on. The 95% probability of a shot from the grassy knoll was entirely dependent on: The microphone turning the corner onto Elm Street at 11 MPH. The microphone turning the corner onto Elm Street during the shooting Z160-Z313, and being close to specific points on the map. Sadly there is no complete film of this sequence to prove point 2 either way, so this is where my animation can help! I plotted a circle where this microphone needs to be, but for most of the time Z160-Z313 it is pointing to a space not occupied by a car or bike. Moreover the nearest bike is some considerable distance away (over 100 feet). Point 1 is also very suspect as the cars and bikes turning that corner average below 10 MPH, especially a bike like McLain's turning the tight inside line which forces the bike down to around 5 MPH. With no empirical evidence supporting 1 & 2 above the 95% claim ceases to be relevant. Abstract discussions of sound waves, echo patterns, and probabilities are great, but without concrete data connecting them to Dealey Plaza I have to regard this as a theory unsupported by the known facts. You rightly say the dictabelt is not a pristine recording and may have momentary glitches, but assessing the audio as a whole, it's very hard to concoct a scenario where the shots were recorded but the sirens were mysteriously absent until 12:33, i.e. over 3 minutes after the shooting stopped. Having said all of that, my ideas are not set in stone so if a plausible explanation can be found for my objections I'm happy to reconsider things. I agree Eddy, the position of the witnesses is crucial to how they interpreted the sounds. For example Pierce Allman and Tina Towner were standing directly in front of the TSBD and heard three well spaced shots which suggests that those noises came from the sixth floor window (a noisy rifle could not be missed at such close range). By contrast those people further away from the TSBD seem to have missed some of the shots (perhaps understandably with a noisy motorcade and the siren). For example James Altgens, Robert Hughes, and Lee Bowers all seemed to miss either the first or last of the bursts of gunfire and they were some distance away from the TSBD. A silenced rifle, or one fired from within a building would indeed attract far less attention, and as you say only be audible to those within a fairly narrow area around the bullet path. Interestingly several witnesses mentioned that the rifle on the sixth floor of the TSBD was poking out of the window so those sound waves would have travelled widely around Dealey Plaza, including echoes and reverberations. I'm skeptical of a concealed gunman on the knoll because there is a lack of positive support for this theory by those witnesses who were closest such as Abraham Zapruder, Marilyn Sitzman, Emmett Hudson, and Charles/Beatrice Hester (and F Lee Mudd assuming he was on the steps with Hudson). For the sake of balance I should say I'm not completely against all conspiracy theories. While compiling my witness survey I was intrigued by the several dozen reliable witnesses that insist a shot was fired about a second or two before the head shot. Not only is this supported by a wide variety of different witnesses in different locations, the Zapruder film exactly matches what the limo driver William Greer said he did in his Warren Commission testimony when he described two shots being fired at and before the head shot (3 seconds after the first shot he heard, which was presumably circa Z220). Taken at face value these witnesses are the strongest evidence of a second gunman I have so far found as a bolt action gun couldn't be operated three times in those 5 seconds (Z220-Z310) and be expected to hit a moving target twice. Dismissing this extra shot as echoes doesn't make sense because it occurs before the head shot, not after.

Thanks John, I'm glad you find the list useful. There are more witnesses that I chose not to include because they were so vague about events, but if you discover any useful witness not on my list please let me know and I will add the details. For the benefit of people who haven't read my handbook, here are the sources I used when compiling the witness names: John McAdams - https://mcadams.posc.mu.edu/shots.htm Josiah Thompson - "Six Seconds In Dallas" appendix A, p.252 https://archive.org/details/SixSecondsInDallas Mike Russ - http://mcadams.posc.mu.edu/russ/wit.htm Pat Speer - Chapters 5-9 http://www.patspeer.com/chapter5%3Athejigsawpuzzle Stewart Galanor - https://www.history-matters.com/analysis/witness/index.htm

The exact number of shots is a tricky one to judge. While I was studying what each of the witnesses said in 1963/4 I came to the conclusion that there were three bursts of noise. Some witnesses are certain that each burst of noise was just a single shot, whereas others are convinced that multiple shots were fired in each section. For example there is AJ Millican who reported 8 shots in 3 parts: 3-2-3. He tells us that the shooting started just as the limo passed him which was Z190-Z220. I think the 2nd burst was Z280-Z330, with the final burst Z370-Z430. Some witnesses missed the first burst, and some missed the final burst, which is why the witnesses disagree so much about the shots and the total duration (those that say the shooting lasted just 5-6 seconds missed the first or last burst). By contrast Charles Brehm agreed with the timing of the three bursts I have suggested, but he said there was only one shot in each section (which is perhaps persuasive as he was a soldier during the war and very familiar with gunshots). In other words I am uncertain about the total shot numbers, but the general pattern of noise is clear (with 3-5 seconds pause between each of the three bursts). The motorbike noise on the dictabelt was probably recorded in the vicinity of the Trade Mart. The timing of the motorcade sirens on Channel 1 about 3-4 minutes after the assassination is exactly the right time for when they turned off Stemmons Freeway, passing the Trade Mart to go to the hospital. One of the reasons it couldn't have been recorded in Dealey Plaza was that it didn't pick up the siren that was set off by the Secret Service follow up car just after the head shot. This siren was set off by Sam Kinney who said: "At this time the second shot was fired and I observed hair flying from the right side of his head. With this, simultaneously with the President’s car, we stepped on the gas. I released the siren at that time" In other words he set the siren off in the seconds following Z313, but this siren doesn't appear on the Channel 1 recording so I deduce that the microphone could not have been located in Dealey Plaza. I understand why people are keen to have an audio recording as that would immediately resolve the issue of how many shots were fired and in what sequence, to a very high level of scientific certainty. One of the largest controversies about this case would be immediately resolved. Sadly I don't believe there is any audio recording of the events in Dealey Plaza so we must revert to old school crime scene investigation with a focus on the witnesses and physical evidence.

Thanks John. I think the crime scene witnesses are very important and are worthy of more study and analysis. Although superficially the witnesses seem to contradict each other, I think it's possible to see beyond this and make progress. For example many witnesses missed the first or last shot (or shots), which means they heard fewer shots in total than were actually fired. The clear sign of this is when a witness describes the whole shooting as lasting just 5-6 seconds, whereas other witnesses think it all lasted at least 10 seconds. Although I have yet to come to any final conclusions regarding total shots fired or the conspiracy angle, if there were three shots fired in just 5-6 seconds as so many witnesses say then there must have been a second gunman. A primitive bolt action gun could not be operated, aimed, and fired three times in 5-6 seconds (especially with two of the shots being accurate enough to hit their intended target). In other words the only witness supported lone gunman theory is if the shots were fired at: Z220, Z310, and Z400. A fourth shot at Z280 or Z190 (as many witnesses suggest) requires a second gun firing, and a probable conspiracy.

This is a tricky puzzle to clear up as there doesn't seem to be a complete film sequence with all of the bikes as they entered Dealey Plaza. I think the solution is the so called "Croft 1" photo: This shows the 3 bikes in front of the Dallas Police lead car on Main Street, which makes sense as 2 of the bikes broke from the group of 5 for some reason as they approached Dealey Plaza from Main Street. Todd Vaughan mentioned this break in formation on page 5 of his very well researched motorcade reference: http://jfk.hood.edu/Collection/Weisberg Subject Index Files/M Disk/Motorcade Route/Item 15.pdf Here is a screenshot from the animation which shows the Croft 1 photo and where all of the bikes are at that point:

You are right John, in terms of numbering the cars sequentially the advanced car comes first. However, because that car doesn't appear in the animation the other numbers all get promoted by 1 which causes this confusion. Because the animation also includes other actors such as witnesses and the theorised dictabelt microphone, there will always be a discrepancy between the official motorcade vehicle numbers and the numbers used as identification in the animation.

The black dog man does look very strange in the Betzner and Willis photos. Josiah Thompson interviewed Marilyn Sitzman back in 1966 which may help identify the person: http://the-puzzle-palace.com/files/sitzman.htm She said: "And another thing that I remember this day: there was a colored couple. I figure they were between 18 and 21, a boy and a girl, sitting on a bench, just almost, oh, parallel with me, on my right side, close to the fence." "And they were eating their lunch, 'cause they had little lunch sacks, and they were drinking coke. The main reason I remember 'em is, after the last shot I recall hearing and the car went down under the triple underpass there, I heard a crash of glass, and I looked over there, and the kids had thrown down their coke bottles, just threw them down and just started running towards the back and I ... Of course, I don't see anything unusual in that because everybody else was running that way, 'cause when I look over on my left side, the people on the hill were all running back the same way too." If this couple continued moving briskly behind the pergola and walked eastwards in front of the TSBD then the shadowy figure could be one or both of these two people as the timing is about right (20-30 seconds to move around the pergola seems reasonable).

I think the dark shadowy figure could be the policeman Joe Marshall Smith who was moving towards the knoll at that time. Due to the nature of the photo it's impossible to say for sure, but judging from the size I suspect the figure is walking along the road outside the TSBD (slightly obscured by the shrubs and trees). It may also be Billy Lovelady or Bill Shelley who were also moving briskly westwards towards the knoll area at that time.

I have just published version 2.1 of Motorcade 63 here: https://www.marktyler.org/mc63.html As always thanks to those who have taken the time to share their thoughts and help me make the work better with each iteration. The video only has a few minor changes, such as the dictabelt audio. Having studied both channels I have concluded that the so called crosstalk is the most reliable sync point about a minute or so after the shots were fired. The detail of this synchronization is in the handbook appendix D.3 where I have itemised the second by second events on both channels relative to the animation clock: https://www.marktyler.org/mc63/mc63_handbook.pdf Although the channels are clearly discontinuous at various early points, I think that in the animation around 12:30:00 both channels are recording continuously in real time from when Jesse Curry mentions approaching the triple underpass. This is seemingly correct judging from the various timed announcements within those few minutes. The big effort I put into this release was an exhaustive survey of 283 witnesses who gave information in statements or interviews regarding the shots that were fired. The full survey data is publicly available here: https://www.marktyler.org/mc63/mc63_dpws.csv A full visualisation of this data is available in the handbook in appendix F (page 120). I have also taken this opportunity to reorganise the handbook so all of the analysis of theories is done relative to the survey results. In some areas the witnesses are collectively fairly certain about what happened in Dealey Plaza, but in other areas they are sharply divided. For example 73% of witnesses heard three shots fired in total, and 75% of reliable witnesses are certain that just a single shot was fired around or before Z225-Z240 when the first unambiguous effects of gunfire are seen in the Zapruder film. By contrast the witnesses are very split on these issues: 58% of reliable witnesses are certain that no more than one shot was fired around the time of Z313, whereas 32% are certain that a second shot was also fired around this time. 54% of reliable witnesses are certain that no shots were fired after Z313, whereas 38% are certain that at least one shot was fired after Z313. 59% of reliable witnesses thought that at least two shots were bunched together somewhere during the shooting, whereas 41% thought the shots were evenly spaced with no bunches. In summary, the most reliable witnesses are evenly split regarding when the third shot was fired: either it was within a second or two of Z313; or it was fired 3-6 seconds after Z313. If both sets of witnesses are correct then there were at least four shots fired that day. Hopefully researchers will find this quantitative and qualitative work useful in evaluating the many theories in this case.

Hi Eddy. It's correct to say that the Wiegman film was played back at 24 FPS. For every 4 original frames, an extra one was added to make this to the ~30 FPS that is the NTSC TV playback rate. However this does not mean that the film was recorded at 24 FPS. In other words you can play a film back at any rate you like, but it was only recorded one way (and due to the mechanical nature of the camera it wasn't necessarily a fixed frame rate). Sadly the Wiegman camera was never studied so we don't have any firm evidence to form an accurate view of its recording rate. By contrast the Zapruder, Nix, and Muchmore cameras were all studied in some detail so we know reasonably well what rate they were recording at on average. The Wiegman camera did have a setting for 24 FPS, but it also had a setting for 32 FPS. In both cases the camera could have been running slightly faster or slower than the advertised speed, so even if we knew which setting was used we couldn't be sure that the camera was behaving as designed. For example in 1967 CBS news studied different Bell & Howell cameras and the recording rates varied between 15 FPS and 20 FPS, when they were all supposed to be recording at 18 FPS. In the absence of experiments the only thing left to do is see if we can measure the Wiegman film against a known film such as the Zapruder film. In this case we are lucky because we have 2 points to measure between the Zapruder film and the Wiegman film. Due to the known positions of the cars as measured in the background of the Zapruder film Z180-Z230, the animation can be used to calculated that Wiegman started filming around Z285-Z300. I have used Z295 in my calculations but there will always be a margin for error as we can't know it exactly due to the deceleration and acceleration around the corner. As Chris has shown we also know that at Z447 both films have a common view of the limo as it sped away from the crime scene. Dale Myers found this to be frame 265 of the Wiegman film, or 11 seconds from the start if the film was recording at 24 FPS. Like Chris, Myers assumed 24 FPS and his view was that Wiegman started filming at Z246 which is 11 seconds before Z447 which is a match. However this must be incorrect because when Wiegman starts filming we see the Mayor's car in front of the traffic lights well past the mid point of the turn here: This cannot possibly be Z246 because at Z255 Altgens takes his photo and the Mayor's car is nowhere in sight: In other words we have a contradiction which means one of our assumptions is incorrect: The Wiegman film was being recorded at 28-32 FPS which allows for the difference from Z246-Z295 and a Zapruder rate of 18.3 FPS. The Zapruder film is missing about 2 seconds worth of frames if the Wiegman film was recorded at 24 FPS and the Zapruder film was recorded at 18.3 FPS. The Zapruder film was being recorded at just 13.8 FPS, i.e. (447-295) / 11 seconds, and Wiegman was recorded at 24 FPS. I favour option number 1 because after viewing the Wiegman film in its entirety I find it a little slow, and by speeding it up I then get to the 28-32 FPS range which matches the films correctly. Option 3 is highly unlikely as it deviates too far from the measured speed of the Zapruder camera (17.6-18.5 FPS via FBI experiments in 1964). Chris argues the case for option number 2 and frame suppression to hide evidence. If this is correct then by implication frames from the Muchmore, Nix, and Bronson films must also have been removed as they were all recording around the head shot when any removals are alleged to have been made. When I studied all of the film frames I didn't notice any problems with continuity or sudden speedups or slowdowns, so I have concluded that the extant film frames are a full and complete record of what happened in 1963. Just for reference here are the animation frames that match the above photos:

Thanks Daniel, I think you are right. Here are a couple of photos of the 1964 Mercury Colony Park Station Wagon: The license plate, lights, corners above the lights, and the small circular area beneath the rear window seem to match. This also looks to be a match for the VIP car in the motorcade as seen in the Willis 6 photo: Credit to Todd Wayne Vaughan's motorcade reference for confirming this car model: http://jfk.hood.edu/Collection/Weisberg Subject Index Files/M Disk/Motorcade Route/Item 15.pdf Now we just need to find a few videos of this car model signalling to turn. I've not found any yet, but if any reader does find a video please share the link so we can try and confirm the Wiegman film frame rate!

Thanks for the video Chris, it's a very clear version, which is nice to have as a reference. It has been brought to my attention by a keen eyed researcher that later in the Wiegman film we see a car signalling left to go into Parkland hospital: This may be able to help nail down the film recording rate if we can find out the make and model of car. Presumably the blinking rate would have been fairly constant and predictable, so we can therefore calculate how many frames are required per signal cycle in real time. Does anyone know what type of car this was? I extracted the frames from the video and found that there were 25 or 26 broadcast frames per cycle. As the film was translated from an assumed original 24 FPS to 30 broadcast FPS, we multiply by 0.8 to return to the original Wiegman frame rate, i.e. 25.5*0.8 = 20.4 original Wiegman frames per side turn signal cycle. If the Wiegman film was recorded at 24 FPS that's 1.18 Hz. If the Wiegman film was recorded at 30 FPS that's 1.47 Hz. Frustratingly both are in the range 1-2 Hz as mentioned here: https://en.wikipedia.org/wiki/Automotive_lighting#Side_turn_signals However, if we find out what car type it was there should be a way to determine whether it's normal blinking rate was closer to 1.18 Hz or 1.47 Hz, and therefore deduce the correct recording rate of the Wiegman film.

The whole of the Wiegman film was shown on the afternoon of the assassination on NBC here at 2:10:50:

Hi Chris. 24 FPS is indeed the rate that the Wiegman film was replayed on TV in 1963, as for each 4 frames in the original film, an extra one was added to get to the ~30 FPS rate for TV. However, the rate that the Wiegman film was recorded at is unknown and can only be estimated relative to other films and human judgement. His Filmo camera had both a 24 FPS setting and 32 FPS, so it's somewhat moot as to which one he was using: https://en.wikipedia.org/wiki/Filmo Even if we knew that, we wouldn't know if the device was running slightly faster or slower than the factory specification, as each camera had its own quirks thanks to their mechanical nature. In terms of verifying or refuting the completeness of the Zapruder film, the recorded frame rate of the Wiegman film is crucial. If it can be proven that the Wiegman film was recorded at 24 FPS, then about 2 seconds is missing from the Zapruder film between Z295 and Z447. Conversely if the Wiegman film is proven to have been recorded around 28-32 FPS then the extant Zapruder film is valid and complete. How can we do this verification objectively? Sadly I'm not sure we can. The closest we get is a Dorman film segment which was recorded concurrently with the Wiegman and Zapruder film for about 6-7 seconds. If we could somehow match that segment to the other films we could deduce the correct frame rate, but sadly I don't think there are enough shared visual elements to do that. The only remaining thing I can think of doing is an eyeball test. Here is the Wiegman film re-coded at 24 FPS, 28 FPS, and 32 FPS: https://drive.google.com/file/d/1Y-Z6gvsWCEUhNd6Zk9-r49F0fAXXZodx/view https://drive.google.com/file/d/1x40-EjFCeJPde9X7vySoHgCJOnQSbdqO/view https://drive.google.com/file/d/1sRb3tRblP6yEmv2ri_EzRzjclwz4gqRM/view Which one looks most natural? I think 28-32 FPS due to the way Charles Hester jumps up near the end. The original 24 FPS video feels a little too slow. It's rather subjective, but I think it's the only way of testing the Wiegman film.

Thanks for the tip about David's article, which does cast reasonable doubt on Oswald firing the shots based on the witness evidence. Like you, I don't think Oswald was merely an innocent bystander. I struggle to believe the curtain rods story and his lack of interest in the motorcade, so I feel he had prior knowledge of what was going to happen and was simply lying to cover his tracks. Whether he was the mastermind of events, or just a bag carrying lackey, I'm not sure. The only certainty is that he fled the scene quickly afterwards, which seems rather suspicious.

What if the rifle was fired 3 times from the sixth floor window, but was fired to distract attention and not to hit anyone? An accurate and reliable gun is not required for this scenario, just something rather noisy that can be seen poking out of a window. In other words Oswald was more of a hired decoy than an innocent patsy.

Here is the latest release of Motorcade 63 (version 2.0): https://www.marktyler.org/mc63.html I added these photos: Powell Dillard 2 Dillard 3 The animation now has a few more interesting witnesses and their movements: Billy Lovelady Gloria Calvery Joe Marshall Smith Edgar Smith Welcome Barnett Carolyn Walther James Powell The Franzen family Amos Euins Howard Brennan I slightly changed the route of the knoll runner and the black dog man, as Marilyn Sitzman said they were a couple who ran behind the pergola and were responsible for a bottle smashing onto the ground. This is probably what Lee Bowers described as a "commotion", as the narrative and timeline matches perfectly. While studying the testimony of the Secret Service agents I noticed that Sam Kinney started his siren in the seconds following the head shot when his car was in the heart of Dealey Plaza. This was corroborated by other witnesses so I consider this to be a major challenge to the dictabelt evidence: How could the microphone pick up gunshots but not a siren? We know that the microphone picked up sirens 2 minutes later on Stemmons freeway, so why not in Dealey Plaza as well? More detail of this work is in the handbook section 9.1.1: https://www.marktyler.org/mc63/mc63_handbook.pdf The audio from the dictabelt recordings has been added to the video along with some other sounds that the witnesses reported. Back in 1963 every witness would have heard each of these noises in a slightly different way. For example the siren would have been loud and dominant to those closest to Secret Service car. This might explain why the Secret Service agents and James Altgens didn't hear the final shot whereas those by the TSBD heard "three well spaced reverberating shots". The final gunshot would have been louder to them as it was closer, and the siren was further away so it was quieter. I have updated the handbook regarding the timings of the shots (section 6). I have concluded that while most witnesses say they heard three shots, they are not talking about the same three shots: some say they were equidistant; and some say they were bunched on top of each other. In other words the "consensus" among witnesses regarding three shots is a numerical illusion which disappears upon close inspection. Many thanks to the people who made suggestions for improvements, and also the researchers whose many decades of work I have used in the book and the video.

Chris, I updated the animation and it should be more accurate for the car positions at Z175 when I publish it in a few weeks time. A notable change seems to be that the Bronson 3 photo had to be changed from Z235 to Z228. I also had to change the Hughes film sync at the point of McLain turning the corner which is now Z150. Otherwise it's just a slight change in the 4 car speeds to worry about. The average Presidential limo speed between the measured key points are as follows: Towner end to Z180 = 11.1 MPH Z180 to Z224 = 10.9 MPH Z224 to Z280 = 11.8 MPH It's not quite the smooth acceleration out of the corner as before, but it's still fairly consistent over the 5-10 seconds in question (i.e. within 1 MPH). Thanks again for spotting the issues and helping improve the accuracy of the animation relative to the photos and films.

The next version of Motorcade 63 could be very revealing if I can't fix this glitch! At the moment I think the car needs to be 4-5 feet further forward around this time. I've made some other interesting discoveries in the last week. For example I think I know who this person is in the Bothun 5 photo: They are also in the Darnell & Couch films wearing dark clothes as they run towards the railway tracks looking for the assassin:

Anything is possible John so I don't rule out suppression of photos or frames. However, the focus for me over the next 6 months as I finish the animation is to concentrate on what evidence is available on the public record. I want the animation to be consistent with the known facts, and so if any odd discrepancies appear then this will support the suppression theories. Time will tell! When you say "shooting occurred in front of the TSBD" I agree with you. At Z185 when I think the shooting started, part of the Presidential limo was directly in front of the south west corner of the TSBD. Of course many other people think the limo was at Z150 or even before Z133 when the shooting started (e.g. Max Holland). I respect the people who think this, but I interpret the evidence differently so I politely disagree and show my workings as to why. Most of the witnesses nearby said the limo was at the lamppost or the signpost when the first shot was fired. Also, with the animation we can see Z185-Z200 fits hand and glove with where the witnesses in the camera cars on Houston Street said they were when the first shot was fired. In other words I'm not merely counting witnesses who explicitly agree with me about the Presidential limo, I'm linking together many different statements from different areas of Dealey Plaza and corroborating a timeline for the shots based on multiple car positions. The Houston Street witnesses also help me prove that the shooting lasted about 12 seconds from start to finish, which in turn corroborates the witness reports from people like Mary Moorman and Jean Hill who insisted they heard shots well after the head shot when the limo was racing towards the underpass bridge.

Thanks for taking the time to look at this Chris. It looks like the Presidential limo in the animation needs to be a little further forward. Helpfully the Betzner photo is soon after at Z186 and it looks like I have the limo and follow up car too far back there as well. The error seems to only affect one of the key points so I shall put this on my to do list and hopefully it won't take too long to fix this mistake. It will change the speeds between Z133 and Z224 somewhat, but hopefully there won't be any strange knock on effects like rapid acceleration and deceleration. By contrast it looks like the VP car and its follow up might be a little bit too far forward so I shall try and fix that at the same time. Well spotted!

Thanks for the references Lewis and Eddy. Taken at face value Zapruder is confirming that the film is the same as when he saw the original version before he handed it over to Life, but he can't vouch for exact frames. This seems plausible as he was unlikely to have counted the frames on the original or the copies before they were handed over. This account contradicts the claims of those who say the whole film is a concoction, with large chunks removed (e.g. the turning of the corner) or recreated in a film studio. However, it does leave open the possibility that the odd frame here or there may have been suppressed, as David and Chris suggested earlier in this thread. While I'm not in a position to prove or disprove these claims, I feel that the authorities would be taking a huge risk in doing this so I suspect this isn't what happened. The car does seem to slow down just before the head shot, and then accelerate soon after but I don't detect any correlation between the change in vehicle momentum relative to JFK and the other passengers. In other words the backwards movement of JFK's head would seem to relate to the impact of the bullet rather than anything else. Perhaps rather than a single cause it was a combination of the jet effect and a muscular reaction? Also, JFK's head was pointed down at a very odd angle at Z312 so this may have contributed to the unusual movements. As well as the obvious ethical issues involved I think it would be scientifically impossible to recreate the exact circumstances we see in the Zapruder film. Knowing the exact sequence events such as: the car speed; the position of JFK; etc; would seem to be far too complex to recreate. As a result I feel the whole area is somewhat difficult to resolve with absolute certainty. Maybe in the future with more complex computer models it may be possible to understand what happened, but for now I feel it's simply impossible to have any certainty on the matter.

The strong head movement is rather difficult to explain, as is the explosion which some gun users have suggested is the result of a frangible bullet rather than the full metal jacket type that came from Oswald's gun. I'm not experienced with either ballistics or medical matters so I must defer to experts in those fields for guidance. I've not studied the Garrison trial very much, but your comment about Zapruder sounds interesting. Is there an online link to this testimony?

No, I don't think the animation proves that any frames have been removed or that the limo stopped. If there had been any removal of frames then the Nix film and the Muchmore film would also need to be changed as they were filming the same scene from a different angle at about the same frame rate. While doing this work, and making all of the required measurements, I didn't detect any glitches or jumps in the car sequences or any other problems that I would expect to see if there had been any evidence destruction. I would suggest that the smoothness of the action in the animation implies that the visual record is complete and has not been tampered with. Proof of more than 3 shots is tricky, as I think there could have been more than 3 shots, but its hard to know for sure. In the Zapruder film we see direct proof of 2 or 3 shots depending on whether there is a missed shot at around Z185, and a wounding shot at around Z215. Proof of multiple gunmen seems to hinge on this 2 second period, and whether there is a second shot or whether there is some kind of delayed reaction to the victim movements that we see at Z224-Z230. John Connally is convinced that the first shot missed him, and if he is correct then there must have been at least 4 shots in total because there was definitely a shot fired well after the head shot (over a dozen witnesses reported this shot). 2 shots in 2 seconds is proof of multiple gunman because Oswald's gun couldn't be operated that quickly. 4 shots in total is proof of a second gunman as only 3 shots were associated with the TSBD, so the second gunman was located elsewhere.

Given the very short time frame between the awareness of the problem to giving the order, I suspect nobody told Roberts to do this. It was just a heat of the moment decision I guess. I assume that they were simply taking evasive action by getting out of the danger zone as soon as possible. If the agents had not been called back then it would have delayed their departure from Dealey Plaza for no benefit. The death of JFK was clearly a tragedy, but it all happened so rapidly I'm not sure anything else could have been done to prevent it in the seconds between the first shot that hit him, and then the fatal shot. Even if the car hadn't slowed, it would still have presented a similar target to the assassin(s). With the first shot fired at Z185 and the fatal shot being fired at Z310, that's less than 7 seconds to do something to block another bullet. Given the positions of the agents when the shooting started I don't think they could have done anything to stop the ambush succeeding.