Reply #67: Everyone in the car would have realized the shot occurred from a few feet away.

[benEzra]

If you don't believe me, go visit a shooting range and stand 3 feet away from someone shooting a .38 revolver. The difference in absolute sound intensity between a revolver 2 yards away and a rifle 50 yards away is on the order of 20^2, or 400 times the intensity, e.g. around 25 dB louder. The people in the car would have FELT the muzzle blast, and there would have been obvious powder burns (visible to the unaided eye) on the back seat. Not to mention that every other bystander standing by the side of the road would have seen the gun in the driver's hand.

Remember, the bystanders had a better view of the limo than Zapruder's camera did (given the limited resolution of the camera).