Ken Rahn of Rhode Island has offered arguments defending the work (or at least the conclusions) of Dr. Vincent Guinn in performing and reporting on NAA testing done for the HSCA.
Here are some issues and questions one might wish to bring up with him:
a. Rahn told me in 1993 that he found many flaws in Guinn's work and relied mostly on the FBI's 1964 testing. His position was that Guinn had made presumptions that were not warranted by his testing data, but got it right, anyway. It's the old WC position: "We did it all wrong, but got the right answers anyway." So Rahn might be asked the following:
* Do you agree with Dr. Guinn's testing methods and his methods of gathering experimental data?
* Do you think that Dr. Guinn's findings based on his lab research with Mannlicher-Carcano ammunition, justified his statement to the HSCA, under oath, that "you simply do not find variations in antimony and silver compositions in Mannlicher-Carcano ammunition"?
*Do you think that Dr. Guinn had done enough laboratory testing of WCC Mannlicher-Carcano ammunition to justifying ANY scientific conclusions about the homogeneity or heterogeneity of the ammunition?
*Are you troubled that Dr. Guinn was unwilling to assign a % possibility to his findings. (Dr. Joe Riley points out that the very essence of scientific inquiry is the ability to assign such probability numbers.)
*Are you satisfied with the mathematics used by Dr. Guinn in calculating his standard deviations? (A mathematician has written to me, pointing out terrible errors made by Guinn in these calculations).
b. I challenged Rahn in 1993 to a test: We would obtain 4-5 Mannlicher-Carcano bullets manufactured by WCC. A panel of persons, while being videotaped, would remove from the lead cores of these bullets 5 fragments. (5 was the number chosen because Guinn was supposedly dealing with 5 key fragments in his Cal-Irvine tests). This could be done in any manner: all 5 from one bullet, 1 from each of the 5, or any other combinations. Rahn or Guinn or anyone else would be called on to take these 5 fragments, remove 5 other fragments of their own choosing and then match the fragments with the bullets from which they came.
Rahn told me that this could not be done. The cores of the individual bullets might be too heterogeneous (which is precisely my point). He said that he would have to have CE 399 itself to do the testing. This led him to concede to me that not only had Lee Harvey Oswald chosen the one type of ammunition (MC) which made possible the heterogeneous (in batches), heterogeneous (in boxes of bullets), homogeneous (claimed for lead in a given bullet) combination - which allowed matching of a given bullet to its fragment. Poor Oswald chose the only individual bullet (perhaps in the world) on which such a match could have been made!
*Mr. Rahn should be asked if he still takes the position that CE 399 could conceivably have been the only M-C bullet in the whole world to which such a match between fragments and core samples could have been made?
*He should be asked if it is not a principal of science that a given experiment or test must be subject to being repeated under precise circumstances by other scientists, who would then obtain the same test results.
*He should be asked if the FBI-Guinn results be obtained by other scientists.
*He should be asked if he is willing to participate in tests under the circumstances described above, to show the alleged homogeneity or heterogeneity of WCC M-C ammunition.
It is important to read very carefully what Rahn is claiming.
He is saying that his analysis of the NAA evidence shows that fragments from a total of 2 bullets were recovered-not more than that. He would also claim that the bullet allegedly found on the stretcher was the source of the bullet fragments in Connally's wrist. He would claim that the other 3 fragments (from JFK's brain) matched bullet fragments found among the car seats.
He would not claim that his analysis proved (or could prove) that CE 399 passed through JFK first. In short, he would argue that two bullets from Oswald hit the two men, but would not claim that he proved the SBT.
But this is really a distinction without a difference. If one bullet hit Connally's wrist, another bullet hit JFK's head and both came from Oswald's rifle, then, by what other method could JFK have been wounded in the neck/throat? This would require a never-found, never-accounted for bullet.