I Posted this on the other forum, I will post it here also as I don't really understand the science of this subject, maybe someone here will. According to the forensic textbooks I have the type of ammunition used in the murders at that time does not use the typical propellants that GSR swabs are designed to detect possibly rendering them meaningless.
Depending on how the home office Laboratory conducted its testing on the hand swabs in 1985 it may be that the entire process was fundamentally flawed. I am over my head when it comes to the science of this but for anyone that is familiar with the subject it might be worth further examination.
Here is part of page 208 of the book Forensic Science From the Crime Scene to the Crime Lab by RICHARD SAFERSTEIN, PH.D. Forensic Science Consultant, Mt. Laurel
However, hand swabbing or the application of an adhesive cannot be
used to detect firings of most .22-caliber rim-fire ammunition. Such ammunition’s
primer may contain only barium or neither barium nor antimonyHere is an extract of page 101 of Current methods in forensic gunshot residue analysis by
A. J. Schwoeble and David L. Exline forensic scientists at RJ Lee Group

The manufactures of Remington rimfire ammunition is ELEY LTD

Now I have obtained a copy of the 1983 patent for that type of ammunition listing the ingredients
however I still cannot be sure its the exact production of the ammo used at whf
