Hi,
Cells found does not necessarily mean that the letter was licked by the sender.You know that, right? How many cells were found? Was saliva found? If there were a few cells, that could be contaminant DNA on the outside of the letter because SFPD did not selectively test only the backs of the stamps and envelopes. Cells can be deposited on the outside of the envelope by someone touching the letter and depositing some cells without any saliva being deposited. Alan Keel told both me and Lafferty that the true Z letters might just as well have been sealed with tap water. If you want to dispute those findings, I suggest you contact Mr. Keel, not me. As for the Exorcist letter, I suggest that one as the second forgery because it is the ONLY 1974 letter on the chart.
Let's say that you can find zero cells on one letter, 12 cells per sq. mm. on another and if a letter were licked you'd be expecting to find something like 1200 cells per sq. mm. You could say for letter two that there was no saliva found but that you found a VERY low concentration of cells, 12 per mm-squared. These cells did not appear because the letter was licked by the sender and there is not enough of them to say that the letter was licked because they are two orders of magnitude too low (12 vs. 1200) for that to be true but "cells were found" even though not nearly enough for the letter to have been licked and in the absence of saliva because they were picked up on the FRONT of the stamp from the environment in various ways.
Mike
