Quote a test showing people will only jiggle their camera while filming each time they hear a gunshot.
Have you read *anything* about the assassination? This is one of the more well-known, well-covered issues in the literature. So is your argument that Zapruder jiggled his camera *three times* "just because" and that he jiggled it three other times in response to gunfire, because your bankrupt theory does not allow for more than three shots? I mean, sheesh, at some point doesn't your brain kick in and say, "Wait a minute! This theory is just absurd!"?
Anyway, moving on from a lost cause (getting Beck to admit anything that conflicts with the lone-gunman theory), although I firmly believe the Zapruder film has been edited, I also believe it contains clear evidence of more than three shots, and that this is why the film, even after being edited, was suppressed.
One key piece of evidence in the film is JFK's dramatic reaction that begins at Z226, a good 20 frames after he has clearly begun to react to a previous external stimulus.
Beginning at Z226, Kennedy's upper body is visibly jolted sharply forward, and the position of his hands and elbows--particularly his elbows--changes dramatically, as they are flung upward and forward. The force and speed of his forward jolt and of the movement of his hands and elbows are quite startling when one watches the sequence from Z226-232 in slow motion. Second only to the head shot, this reaction is the most obvious in the Zapruder film, with Connally's Z236-232 reaction running a close third.
But here's the fatal problem for the lone-gunman theory: Kennedy clearly, clearly begins to react to a different external stimulus at around Z188, when his cheeks puff. At Z200, Kennedy's movements suddenly freeze and his right hand abruptly stops in the middle of a waving motion. He also begins to rapidly turn his head to the left toward his wife. By Z207 he has his hands up to his face. The HSCA PEP acknowledged these movements. They are obvious to anyone who is willing to allow their eyes to see them.
However, we see the obvious result of a bullet striking him in the back starting at Z226 when he is visibly knocked forward and his hands and elbows are flung upward and forward. This is clearly the back shot.
So, we have one non-fatal shot reaction from Z188-207, as even the HSCA photo evidence panel acknowledged. Then we have the second non-fatal shot reaction, the second-most obvious shot reaction in the film, from Z226-232. Then we have the head shot at Z313. And even the Warren Commission admitted there was one missed shot. That's four shots right there, and that's not counting Connally's dramatic shot reaction from Z233-240 and the clear indications of shot reactions starting at around Z154.