Ah-ha! I knew it! I just knew it! I knew there was something wrong with Joe Elliott’s description of the 1948 U.S. Army ballistics test film of a goat being shot in the head. When I pointed out that the backward movement of JFK’s head in the Zapruder film begins too quickly (1/18th/second or 55 milliseconds) to have been caused by a neuromuscular reaction, Elliott claimed that the goat film proved otherwise:
. . . there is a video of a goat which was shot through the head which causes its body to move pretty forcibly. . . . The goat starts moving its body 40 milliseconds after the bullet struck. So, the very next frame, roughly 55 milliseconds later, JFK’s head starts moving as well.
Leaving aside the important fact that the goat’s reaction movements are very different from JFK’s reaction movements, on a hunch, I reviewed ballistics expert Larry Sturdivan’s HSCA testimony on the 1948 goat ballistics test, which I had not read for at least 20 years. I discovered that the film that Elliott has been citing was not shot in real time, and that the film that was shot in real time shows that the goat did not begin to react until about 1,000 milliseconds after the bullet’s impact.
The film that Elliott has been citing was taken at 2,400 frames per second (fps). At that film speed, yes, the goat begins to react right around 40 milliseconds after the bullet hits the goat’s head. But, as Sturdivan explained to the HSCA, when you view the real-time film of the same goat test, the one taken at 24 fps, the goat’s reaction “takes place about a second after the shot and then slowly dissipates and you will see the goat slump” (1 HSCA 416).
“About a second” equals about 1,000 milliseconds. There are 1,000 milliseconds in 1 second. So if the goat began to react “about a second after the shot,” then it began to react about 1,000 milliseconds after the shot. We can reasonably infer that when Sturdivan said "about a second," he meant 800-1100 milliseconds, or perhaps 800-1000 milliseconds, or perhaps 900-1000 milliseconds.
Sturdivan was nice enough to explain that the 24 fps film was a “normal” view and “real time”:
The first sequence will be a normal 24-frame-per-second view of this. This is a real time. (1 HSCA 416)
Sturdivan then explained that the second sequence, which is the one that Elliott has been citing, was taken at 2,400 fps, and that in that 2,400-fps film, yes, the goat’s reaction begins about 40 milliseconds, or “four one-hundredths,” after bullet impact:
Now, this sequence will show the same goat, exactly the same shot, but in this case the movies are taken at 2,400. frames per second. . . .
Four one-hundredths of a second after that impact then the neuromuscular reaction that I described begins to happen. (1 HSCA 416-417)
“Mystery” solved! I say “mystery” because I was frankly a bit baffled by the seemingly impossible speed of the goat’s reaction in the film that Elliott cited. I attributed it to the many differences between goat and human neurobiology and neurophysics (not to mention that the goat’s reaction movements differ markedly from JFK’s). But I also read that goat/sheep/dog/horse and human neuromuscular reaction times are similar—not identical, but similar. Every source I checked said that the fastest human neuromuscular reactions ranged in speed from 100 milliseconds in a few cases to around 200-600 milliseconds in most cases.
When the HSCA asked forensic pathologist Dr. Cyril Wecht about the neuromuscular-reaction theory, he rejected it because he said that the fastest time for such a reaction was about 100 milliseconds, but JFK's head starts to move just 55 milliseconds after bullet impact. Dr. Wecht's statement about human neuromuscular reaction times was correct. A study published in
Scientific American found that the absolute fastest neuromuscular reaction time was 100 milliseconds, with the slower ones being 400-600 milliseconds (
https://www.scientificamerican.com/article/bring-science-home-reaction-time/). And remember that we're talking about a reaction that involved moving Kennedy's head and upper body, not the flick of two fingers or an eyelid, and not a startle reflex from auditory simulation.
Anyway, to recap: The goat film that Elliott has been citing was not filmed in real time but in 2,400 fps. The real-time film of the same goat and the same test shows that the goat’s reaction did not begin until about 1,000 milliseconds after the bullet hit the skull. Therefore, the goat film argues powerfully against the theory that JFK’s backward movement could have been caused by a neuromuscular reaction. Also, in the Zapruder film, JFK's backward movement begins just 55 milliseconds after bullet impact, far too soon to have been caused by a neuromuscular reaction--the absolute fastest human neuromuscular reaction time is 100 milliseconds, and the normal range for such reactions is from 200 to 600 milliseconds.