**A Review Of The Rahn-Sturdivan Approach**

We have now established that this article got the wrong answer because it relied too much on metallurgical speculation and didn't use available data to check itself. Here we review the major alternative approach, the steps taken by Rahn and Sturdivan in their two papers of 2004, and show how they differ from the metallurgical approach.

(1) Note that the five fragments fell into two
well-defined groups (by their antimony concentrations), both in the FBI's runs
in 1964 and Dr. Guinn's runs in 1977 (which used different pieces of the
fragments).

(2) Use the General Linear Model on run 4 of the FBI's data
to determine that the chance of these groups arising randomly from five bullets
or planted samples fell between one in ten thousand and one in a hundred
thousand. (In other words, the groups are not random.)

(3) Use Guinn's data from the 14 test bullets to establish
that the antimony (from the four production runs grouped together) is
distributed log-normally.

(4) Note that the antimony from the individual production
runs shows indistinguishable distributions—the
four lots were the same. (Among other things, this shows that the 14 bullets
were effectively random samples of the four production runs.)

(5) Use the combined log-normal distribution to calculate
the probability that any one of the fragments in the groups might have arisen by
chance (from a third bullet or a planted fragment), and get 2%
to 3%.
(In other words, that didn't happen, either.)

(6) Use the resulting genuineness of the groups to derive
other important conclusions (no conspiracy involving a second gunman that hit
either of the men, the fragments not planted, Oswald's rifle fired that day,
location of rear had wound rendered irrelevant, location of back wound rendered
irrelevant, best shooting scenario provided, and the NAA serving as Rosetta
Stone for the assassination by tying together the core physical evidence).

Note how this approach maximizes the use of available data and minimizes assumptions and theoretical constructs. It is as grounded as humanly possible. Given its strong results and implications, it is no wonder that so many JFK conspiracists have come out of the woodwork to attack it. Yet so far, no one has managed to touch it, in spite of all the heavy rhetoric to the contrary.