[deks]

Thank you for your reply. To me, Kennedy’s head appears to be still at the moment of the head shot (see the small motion picture on the right in the link below).

Then the stop motion of two frames shows that his head snaps sharply forward in about 1/18 of a second when hit - that is the time from frame 312 to 313 (the Zapruder film is about 18 frames per second according to a source).

http://users.skynet.be/mar/Eng/Headshot/back&left-eng.htm#Sommet

[Windflier]

To me, Kennedy’s head appears to be still at the moment of the head shot (see the small motion picture on the right in the link below).

True, but that looped clip shows Kennedy after the first shot was fired. He'd already slumped forward, and you can clearly see Jackie reaching over to him in reaction to it.

One thing the clip clearly does show, is the violent backward motion of JFK's head at the moment of the second shot. A kinetic force applied from the rear is physically incapable of causing that reaction. If the head shot came from the rear, JFK should have been propelled forward, which we don't see.

[Sans-Culotte]

Thanks for posting some good links!