I was referring to Sturdivan's email to Stuart Wexler that is referred to in the OP in which he acknowledges that the fragment is seen on both xray views. He says it "seems to have great[er] optical density thin-face than it does edgewise":
- "I’m not sure just what that 6.5 mm fragment is. One thing I’m sure it is NOT is a cross-section from the interior of a bullet. I have seen literally thousands of bullets, deformed and undeformed, after penetrating tissue and tissue simulants. Some were bent, some torn in two or more pieces, but to have a cross-section sheared out is physically impossible. That fragment has a lot of mystery associated with it. Some have said it was a piece of the jacket, sheared off by the bone and left on the outside of the skull. I’ve never seen a perfectly round piece of bullet jacket in any wound. Furthermore, the fragment seems to have great optical density thin-face on [the frontal X-ray] than it does edgewise [on the lateral X-ray]….The only thing I can think is that it is an artifact (e-mail from Larry Sturdivan to Stuart Wexler on 9 March 1998). " [as quoted in Mantik's 2015 article "The John F. Kennedy Autopsy x-Rays: The Sage of the Largest "Metallic Fragment"
Maybe not when he wrote his book. He is not an expert in interpreting x-rays and he does not appear to have consulted anyone who is.
While it is not impossible that the bright object in the frontal X-ray could be an artifact, one should not adopt such an explanation if it can be explained otherwise. I see no reason why this bright object could not be the 7x2 mm fragment that was recovered from the autopsy. Always adopt the simpler theory over a more contrived one, unless the evidence is strong. And the evidence that this must be an artifact is not strong at all.
The logical conclusion? The bright object was the 7x2 mm fragment. Recovered form near the front of the skull. Just as the autopsy doctors maintained. No evidence of a "cowlick" entry point for the bullet.
I agree with you. Sturdivan was not an expert of x-rays. No one is going to be an expert on all the technical fields related to this case. And, I suppose there is only a finite amount of time one can devote to writing a book so getting the time to consult with all these experts can be a problem. And no one is ever going to write an error free book.
Still, on ballistic questions, the velocities bullets will be deformed by flesh, or by bone, one what sort of damage a bullet may receive when it creates certain wounds, Sturdivan was an expert with a good deal of experience observing real ballistic experiments.
Another point on this subject, Sturdivan was right to say this fragment could not be a bullet fragment left right in the position the bullet entered the skull. His experience with ballistic shows that this scenario would not happen, at least not with a WCC/MC bullet at pretty close to muzzle velocity.
