Gun Shot Residue (GSR) Tests?

[Pat Speer]

1 hour ago, Bill Fite said:

@Pat Speer  Thank you for all the effort you put into this and the clear explanation of all the results of the GSR / NAA tests and experimental setup.

I've been looking for more details on the NAA tests for quite a while.

Very well done and also well-written.

Thanks, Bill. 

[Gerry Down]

18 hours ago, Pat Speer said:

This is all discussed in chapter 4f on my website. They stopped performing the nitrate test performed by the DPD within a few years of the shooting. But the use of NAA to uncover gsr on wax casts is still presumed to be solid science. The problem was that it was very expensive. And was replaced by a less expensive test, that is still performed today. But the results provided Weisberg, and discussed in chapter 4f, are still valid. 

If I commit a homicide today, will the police test my hands for nitrates?

[Pat Speer]

35 minutes ago, Gerry Down said:

If I commit a homicide today, will the police test my hands for nitrates?

NO, but they may test them for gsr. The test performed on Oswald by the DPD was one in which the wax casts were exposed to a chemical, which resulted in purple specks on the casts where nitrates were present. But the loose term nitrates included elements that were not related to gunshot residue. The Neutron Activation tests later performed by the FBI, however, could isolate out barium and antimony, the primary components in gunshot residue. Both elements were found to be present on Oswald's hands in numbers sufficient to claim he'd handled a weapon. But the FBI testified, in pre-scripted testimony, that they could not come to a decision regarding the cheek cast because there was too much barium on the outside of the cast. Well, this led me to wonder "Well, what about antimony? Since both barium and antimony need be present in sufficient numbers to claim a positive result, what about antimony? How much was found on the cheek cast?" After years of searching I obtained the papers that provided the answer--these were papers provided Harold Weisberg after he sued the Atomic Energy Commission and FBI for materials related to the NAA testing of the magic bullet and wrist fragment. In any event, within these papers were the results for antimony, along with a control test performed by the FBI. And I then compared these to a number of other controls performed by nuclear physicist Vincent Guinn, that were never provided the WC but were published in a 1965 paper for the Dept. of Commerce.

And these strongly suggest (I would say prove but I would like to get some feedback from an expert on these matters) that the number for antimony was insufficient to claim Oswald had fired a rifle.

Now, back to your original question. In the years subsequent to the assassination a cheaper alternative was developed to assist officers trying to establish the presence of gun shot residue on a suspect's hands. And these tests are still performed today. 

So...to sum it all up. Oswald passed a test that was suggestive of his innocence--akin to passing a lie detector test. It did not prove his innocence, but it suggested as much, and this scared the FBI into concealing these test results from the public. 

 

Edited March 29 by Pat Speer

[Gerry Down]

16 minutes ago, Pat Speer said:

NO, but they may test them for gsr. The test performed on Oswald by the DPD was one in which the wax casts were exposed to a chemical, which resulted in purple specks on the casts where nitrates were present. But the loose term nitrates included elements that were not related to gunshot residue. The Neutron Activation tests later performed by the FBI, however, could isolate out barium and antimony, the primary components in gunshot residue. Both elements were found to be present on Oswald's hands in numbers sufficient to claim he'd handled a weapon. But the FBI testified, in pre-scripted testimony, that they could not come to a decision regarding the cheek cast because there was too much barium on the outside of the cast. Well, this led me to wonder "Well, what about antimony? Since both barium and antimony need be present in sufficient numbers to claim a positive result, what about antimony? How much was found on the cheek cast?" After years of searching I obtained the papers that provided the answer--these were papers provided Harold Weisberg after he sued the Atomic Energy Commission and FBI for materials related to the NAA testing of the magic bullet and wrist fragment. In any event, within these papers were the results for antimony, along with a control test performed by the FBI. And I then compared these to a number of other controls performed by nuclear physicist Vincent Guinn, that were never provided the WC but were published in a 1965 paper for the Dept. of Commerce.

And these strongly suggest (I would say prove but I would like to get some feedback from an expert on these matters) that the number for antimony was insufficient to claim Oswald had fired a rifle.

Now, back to your original question. In the years subsequent to the assassination a cheaper alternative was developed to assist officers trying to establish the presence of gun shot residue on a suspect's hands. And these tests are still performed today. 

So...to sum it all up. Oswald passed a test that was suggestive of his innocence--akin to passing a lie detector test. It did not prove his innocence, but it suggested as much, and this scared the FBI into concealing these test results from the public. 

 

Thanks for this info

[Benjamin Cole]

More from Pat Speer's excellent website:

And internal FBI memo regarding paraffin casts...

"He (Guinn, running tests on paraffin casts) advised that there appears that triple firing of this rifle will leave unambiguous positive tests every time on the paraffin casts. It further appears that washing the casts with diphenylbenzidine does remove one of the characteristic elements (barium) but such washings do not remove all of the other characteristic element in powder residues (antimony). Further be advised that the tests to date indicate that powder residues are deposited on both cheeks of the shooter after the rifle is fired either one time or three times. It appears, he added, that these results can be obtained even if the paraffin casts are made 2 1/2 hours after shooting the rifle providing that the skin of the shooter has not been washed in the meantime.

Really. 

This is not adding up for "LHO is proved innocent." 

1. The paraffin cast was placed on LHO's cheek more than eight hours after the JFKA, not 2 1/2 hours. This memo seems to suggest some sort of time limit at two to three hours.

2. "providing that the skin of the shooter has not been washed."  LHO may have washed his face at his rooming house, or the Texas Theater. He also may have perspired, which is also known to remove GSRs. 

3. LHO may have fired only once on 11/22, not three times. I suspect this, as most earwitnesses descrive the first shot as different in pitch and volume from the succeeding shot. 

Edited March 30 by Benjamin Cole