Who was the "agent" patrolman Joe Smith encountered behind grassy knoll?

[Jack Trojan]

Your "revisited study" is just an assertion made by a guy named David Wimp, and it's nothing more than some wishful thinking on his part.  If you actually look at frames 312 and 313, you will see Kennedy's head translate forward rotationally, with a center of rotation somewhere in JFK's neck. Exactly where you'd expect it to be if JFK's head suddenly nodded forwards due to a blow from behind. If this were due to blurring --if Zapruder suddenly rotated his camera about the line of sight-- the the amount of blur would increase the further you get away from the center of rotation. Were that true, the left and right edges of the image would be a mostly-vertically streaky mess. But they aren't. The blurring in frame 313 is actually horizontal and linear, and linear blurring can't be responsible for the rotational motion of the image of JFK's head.

This isn't rocket science. I revisited the study myself and found the film speed created too much motion blur to claim the head moves forward. Also, any detectable forward motion is minuscule if it only transpires over 2 frames @ 1/18 frames/sec and can't be attributed to anything. Besides, are you claiming that a tiny bit of forward motion negates back and to the left? All the head motion could have been caused by the frangible bullet, which did not come from behind. MCs don't fire dumdum bullets.

Go ahead and post the animated GIF of frames 312 and 313 and show us the forward head motion over .05 secs and back up your claim that only 1 shot came from behind. I will show you why you are FOS.

That's quite a segue. Someone actually paid attention to you, so you proudly unpacked everything from your crank-box to show it off.  But it's beside the point here, and most of it is a lot of baseless assertion on your part, and not worth anyone else's time. If you want to go into JFK's motion in the films, I'm in. If you're just going to assert clouds of side issues, then you'll just be wasting everyone's time, including yours.

LOL. An amateur says what?

[Ted Shields]

Prove it.

Clear as day.

[Royell Storing]

Clear as day.

    Not only has JFK just been shot in the Neck, but Jackie is also PULLING DOWNWARD on his Wrist/Arm. The clarity of these Images as technological advancements permits, bring other considerations into the discussion. The JFK Head Movement immediately after the Kill Shot is one of these issues. Jackie pulling DOWNWARD on JFK's Wrist/Arm would certainly also cause his head to move.

[Mitch Todd]

This isn't rocket science. I revisited the study myself and found the film speed created too much motion blur to claim the head moves forward.

OIC. The "revisit" of "the study" is your own. So then, where do we find this study of yours, it's assumptions, it's calculations, it's results, and it's conclusions?  If nothing else, it should be entertaining.

Also, any detectable forward motion is minuscule if it only transpires over 2 frames @ 1/18 frames/sec and can't be attributed to anything. Besides, are you claiming that a tiny bit of forward motion negates back and to the left?

The collision of bullet on body is completely over by the end of frame 313. All of the momentum has been transferred. All of the acceleration caused by the impact has happened. Any change in motion seen between z313 and the succeeding frames is due to some other force being applied to JFK's body. Any physicist will tell you this. JFK's head is fairly still up to frame 312, accelerates forwards between 312 and 313, the accelerates backwards in the frames just after 313. Whatever caused the backward motion, then, cannot have been caused by the bullet that created the ugly havoc seen in frame 313. Any physicist will also tell you this.

All the head motion could have been caused by the frangible bullet, which did not come from behind. MCs don't fire dumdum bullets.

"Could have been caused." Nice weasel wording at a time you really need something really concrete in order to be taken seriously.

You need to understand what a "frangible" bullet it vis-a-vis a "dumdum" bullet. The former is made from compressed powder that is weakly bonded together so that it shatters on impact. The latter is, strictly speaking, an early version of the .303 British round made at the Imperial arsenal in Dum-Dum India. It was identical to the early .303 FMJ bullets, except that the jacket was open at the tip. That is, a Dum-Dum bullet was a early soft-nosed bullet. And yes, you can get soft-nosed ammunition for the Carcano:

https://www.ammunitiontogo.com/index.php/cName/65-carcano-soft-point

You also need to explain why you think a "frangible" bullet had to have been used. Edgewood Arsenal and John Lattimer have independently demonstrated that WCC 6.5mm FMJ bullets will fragment when they hit a human head, and create nasty, explosive wounds in the process. For that matter, 5.56 NATO is (in)famous for it's tendency to fragment while passing through soft tissue, even when it doesn't hit any bone. Dr ML Fackler pointed out that the Bundeswehr's steel-jacketed 7.62x51 bullets will do the same, just bigger.

Go ahead and post the animated GIF of frames 312 and 313 and show us the forward head motion over .05 secs and back up your claim that only 1 shot came from behind. I will show you why you are FOS.

Apparently, you're too lazy to look for yourself. Someone else already put up a couple. But I can drop a couple more:

LOL. An amateur says what?

Ameteurs say things like "plasma" and "frangible bullet"

[Mitch Todd]

    Not only has JFK just been shot in the Neck, but Jackie is also PULLING DOWNWARD on his Wrist/Arm. The clarity of these Images as technological advancements permits, bring other considerations into the discussion. The JFK Head Movement immediately after the Kill Shot is one of these issues. Jackie pulling DOWNWARD on JFK's Wrist/Arm would certainly also cause his head to move.

Gold star for you today Mr Storing! You've just pointed out something very important that few people, LN or CT, ever bother to consider.

[Jack Trojan]

OIC. The "revisit" of "the study" is your own. So then, where do we find this study of yours, it's assumptions, it's calculations, it's results, and it's conclusions?  If nothing else, it should be entertaining.

LOL. Like I said before, this isn't rocket science. I simply matched up the 2 frames of film and accounted for the camera shake. You didn't do that. You made the classic mistake of lining up the images at the leading edge of the motion blur in 313. Look at Connally's head stretch horizontally. Everything in motion in 313 is accentuated horizontally. It gives the illusion the head moves forward slightly, but not enough to rule out camera shake and not enough to claim it was a shot from behind. These are not high res still images we are looking at here. And you still haven't explained how a shot from behind (which could have been part of the turkey shoot but you can't prove it) negates the other 2 shots from the overpass and the knoll. It doesn't matter to me if there were 3 shots, but you seem to want it to be a single FMJ bullet shot by a LN with a crap rifle and a wonky scope that moved JFK's head slightly forward then violently back and to the left. I call BS.

I did my experiment 6 years ago when I stabilized the Z film to make a 3D version (you need red/cyan glasses).

From the stabilized data I plotted the vertical component of the camera shake looking for jiggles from gunshots.

[Mitch Todd]

LOL. Like I said before, this isn't rocket science. I simply matched up the 2 frames of film and accounted for the camera shake. You didn't do that. You made the classic mistake of lining up the images at the leading edge of the motion blur in 313. Look at Connally's head stretch horizontally. Everything in motion in 313 is accentuated horizontally. It gives the illusion the head moves forward slightly, but not enough to rule out camera shake and not enough to claim it was a shot from behind. These are not high res still images we are looking at here.

I didn't actually create any of those GIF's. People have been creating animated images of the 313 shot for better than 20 years, and I decided to give you multiple samples specifically to show that it's not just one thing done by one guy one way. Only one of them appears to have been lined up at the front edges of blurs. I guess you like to jump to conclusions. In any case, your objection is just unfounded. The blurring is caused by the motion of the camera. Therefore, every point in the image is blurred the same amount, and there shouldn't no apparent relative motion between blurred objects in the image unless one of them actually is moving relative to the other.

My other point --the more important one, really-- you simply failed to address it at all. The blurring is linear; as you say, it's "accentuated horizontally." But JFK's head actually *rotates* forwards and downwards between frame 312 and 313. Linear movement of the camera will not cause that to happen. It can't be caused by the camera rotating, either. First off, everything else in the image would be seen rotating at the same angular rate, were it true. Also, the length of the blurs would increase with the radial distance from the center of rotation: objects further away from the CoR would be much more blurred than those close to it. That simply doesn't happen in frame 31I the blurring can't account for this rotation, the only alternative is that JFK's head is rotating forwards and downwards. Just as if a force was suddenly applied to the back of his head. Imagine that.

You claim to have "accounted for the camera shake" but have yet to explain how. Answering a question about a vague claim of yours with another vague claim isn't going to impress anyone.
 

And you still haven't explained how a shot from behind (which could have been part of the turkey shoot but you can't prove it) negates the other 2 shots from the overpass and the knoll. It doesn't matter to me if there were 3 shots, but you seem to want it to be a single FMJ bullet shot by a LN with a crap rifle and a wonky scope that moved JFK's head slightly forward then violently back and to the left. I call BS.

You have yet to demonstrate that there ever was a grassy knoll shot, not to mention a shot from the overpass. You seem to just assume them, and believe that everyone else should just follow follow along. Good luck with that.

I did my experiment 6 years ago when I stabilized the Z film to make a 3D version (you need red/cyan glasses).

From the stabilized data I plotted the vertical component of the camera shake looking for jiggles from gunshots.

That's great, at least in the sense that someone is looking at the y-axis jumps of the camera. However, abs(dY)-Ybar statement doesn't make sense. If you're looking for variance in the direction the camera is pointing, all you need is the delta Y component.