LHO, GSR, and 2.5 Hours

[Benjamin Cole]

Pat Speer has a formidable website devoted to the JFKA, recommended for all. 

Chapter 4f is devoted to paraffin casts. 

There is this curious paragraph:

"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.

---30---

That sure is a strange amount of time to mention, 2.5 hours. That's 150 minutes. Does this mean that even the neutron activation analysis (NAA)   tests become non-dispositive after 150 minutes? Guinn sure seems to suggest as much. The phrase "even if" suggests nearing a time limit.

LHO had a paraffin cast made more than eight (8) hours after having possibly fired a rifle. 

And, yes, again the mention that a simple washing the face would eliminate even traces of antimony, evidently the most resilient of GSRs. 

LHO might have washed his face either in the rooming house he lived and visited, or the Texas Theater. It is said LHO did not take a bathroom break in custody before the paraffin test. But he was in custody for more than six hours before the tests were conducted. A very strong bladder perhaps.  Would records be kept of bathroom breaks? 

And, of course, LHO, if a CIA asset, may have been trained in spycraft, possibly to assassinate Castro or others, and may have used a prophylactic while shooting, such as paper taped to his face (plenty of that in the TSBD). 

IMHO, the negative LHO paraffin cheek test is not dispositive. 

 

[Bill Fite]

4 hours ago, Benjamin Cole said:

And, yes, again the mention that a simple washing the face would eliminate even traces of antimony, evidently the most resilient of GSRs. 

Correct me if I'm wrong, but

• The NAA was positive for the casts from the hands, but could have been caused by handling printed materials among other items - books for example.
• So - don't most people wash their hands when using the toilet?
• Do most people wash their hands more thoroughly than their face?
• If LHO's washing was to remove GSRs why would he not concentrate on his hands?

I don't follow the assumption that he would wash the GSRs off his face but not his hands.

Edited April 2 by Bill Fite

[Benjamin Cole]

4 hours ago, Bill Fite said:

Correct me if I'm wrong, but

• The NAA was positive for the casts from the hands, but could have been caused by handling printed materials among other items - books for example.
• So - don't most people wash their hands when using the toilet?
• Do most people wash their hands more thoroughly than their face?
• If LHO's washing was to remove GSRs why would he not concentrate on his hands?

I don't follow the assumption that he would wash the GSRs off his face but not his hands.

BF--

Thanks for your comments. 

It turns out, there were many, many sources for false and real positives on LHO hands.

Even sitting in a police car, which LHO did, can result in false positive on the hands, or touching objects in a police station. This is because police officers, who often practice shooting, carry GSR around.  It is even said that fingerprint inks can result in GSR false positives. 

Or, LHO is used a paper barrier on his face in the TSBD, but when surprised by Tippit, then fired at Tippit. 

Or, LHO washed his lightly exposed face, perhaps at the Texas Theater, with the palms of his hands, but did not thoroughly wash the backs of his hands. 

However, the big takeaway is Guinn saying it "appears, he added, that these (NAA) results can be obtained even if the paraffin casts are made 2 1/2 hours after shooting the rifle."

Guinn seems to be saying 2.5 hours is the upper time limit for an accurate GSR NAA test. 

But LHO casts were made more than eight hours after his purported shooting. In other words, the true GSR on LHO's face simply dissipated, perhaps through perspiration, or wiping his face with a cloth, or washing, before GST testing was done. 

Later, after the JFKA, LHO touched the one or several of many items that can bring about a false positive on the hands. 

As I say, IMHO, the GSR test is not dispositive. That does not mean I conclude LHO is guilty or innocent. 

I would not convict or exonerate LHO on the GSR test. 

But, each to his own. 

 

Edited April 2 by Benjamin Cole

[Bill Fite]

2 hours ago, Benjamin Cole said:

the big takeaway is Guinn saying it "appears, he added, that these (NAA) results can be obtained even if the paraffin casts are made 2 1/2 hours after shooting the rifle."

another question, actually 2:

Is this the same Guinn ran the NAA tests comparing the chemical composition of the MC bullets and refused to report the statistical confidence in his conclusions which were later refuted with 95% confidence?

Where does the 2.5 hour estimate come from? experiments or guessing?

Quote

On the crucial work of Randich and Grant published in the Journal of Forensic Science which completely demolishes the validity of neutron activation analysis for the comparison of bullet lead, touted by the HSCA on the basis of Vincent Guinn's claims.

https://www.kennedysandking.com/john-f-kennedy-articles/death-of-the-naa-verdict

I don't know if the 2.5 hours is the upper limit or how it was arrived at, but Guinn seems to have been mistaken in the past.

Edited April 2 by Bill Fite

[Benjamin Cole]

31 minutes ago, Bill Fite said:

another question, actually 2:

Is this the same Guinn ran the NAA tests comparing the chemical composition of the MC bullets and refused to report the statistical confidence in his conclusions which were later refuted with 95% confidence?

Where does the 2.5 hour estimate come from? experiments or guessing?

I don't know if the 2.5 hours is the upper limit or how it was arrived at, but Guinn seems to have been mistaken in the past.

BF--Thanks for your comments. 

Yes, ironically, it was the very same Guinn. 

Bullets: Yes, from my reading, Guinn failed to take into account that manufacturers of lead used in bullets do not precisely control for quality, and mix and match bullets from different production runs, and even within a bullet there are variations in elements. 

Casts: I do not have a definitive answer why Guinn said that paraffin casts could be taken on a suspect up to 2.5 hours after a shooting, and be reliable. That strongly suggests Guinn tried testing after 3 hours, and found results unreliable--too many false negatives. It is quite a statement to make, when LHO's cast had been taken 8 hours after he possibly fired a rifle. 

Maybe Pat Speer knows. 

To be sure, Guinn, or anyone can make mistakes. I made one in 1983 and then another one in 1995, for example. 

[Pat Speer]

2 hours ago, Benjamin Cole said:

BF--Thanks for your comments. 

Yes, ironically, it was the very same Guinn. 

Bullets: Yes, from my reading, Guinn failed to take into account that manufacturers of lead used in bullets do not precisely control for quality, and mix and match bullets from different production runs, and even within a bullet there are variations in elements. 

Casts: I do not have a definitive answer why Guinn said that paraffin casts could be taken on a suspect up to 2.5 hours after a shooting, and be reliable. That strongly suggests Guinn tried testing after 3 hours, and found results unreliable--too many false negatives. It is quite a statement to make, when LHO's cast had been taken 8 hours after he possibly fired a rifle. 

Maybe Pat Speer knows. 

To be sure, Guinn, or anyone can make mistakes. I made one in 1983 and then another one in 1995, for example. 

To my recollection he didn't run tests with any delay beyond 2 1/2 hours to determine how long one could expect a positive result. He decided to test at 2 1/2 hours, and received a positive result. 

From chapter 4f...

(Note: a subsequent study by Vincent Guinn would come to demonstrate that, under laboratory conditions, gunshot residue could be found on suspects as long as 24 hours after a shooting. A similar study by S.S. Krishnan published in 1974 would similarly claim "residue can remain for up to 17h during normal activity, but can be quickly removed by vigorous scrubbing with soap and water." A second study by Krishnan published in 1977 would support this, moreover, by listing a homicide where gunshot residue was found on the hands of a suspect 24 hours after the shooting. While Oswald's odyssey after the shooting was far from what one would expect to find in a laboratory, it was also far less taxing than 17h of normal activity. As a consequence there is nothing in his saga to make one think the residue on his hands, face, and clothes that would be apparent should he have fired a rifle, would have vanished. From May 31 to June 3, 2005, the FBI crime lab held a symposium on gunshot residue analysis. One of the issues discussed was time limits, a time after which the various crime labs present at the symposium would refuse to conduct a test for gunshot residue. According to a summary of this symposium, found on the FBI's website, "Many participants stated that an acceptable cutoff time is 4 to 6 hours after the shooting event, whereas some felt that up to 8 hours was appropriate. Still others were comfortable accepting lifts taken more than 12 hours after the shooting." It was also noted that the FBI's cut-off was 5 hours. A 2006 article on Scienceevidence.com similarly notes that in Saunders v the State of Texas, Aug. 12 2006, "The State’s expert...testified that the time guideline for gunshot residue tests is four hours because of the diminished likelihood of finding the elements necessary for a positive result. The expert testified that it was possible, however, for the test to produce a positive finding even after six or eight hours, but such findings are described as inconclusive. They are not referred to as 'unreliable,' however, because the problem is the likelihood of the evidence disappearing, not the presence of a false positive."

Also

The acceptance of gunshot residue tests of the face has, in fact, in some ways, surpassed even that of gunshot residue tests of the hands. The Elsevier Encyclopedia of Forensic Sciences, published 2000, notes: "In the case of a living shooter, the gunshot residue may be removed by washing the hands; it may also be rubbed off the hands onto clothing. Because of the possibility that gunshot residue may be deliberately removed or inadvertently lost from a shooter's hands other sources of gunshot residue should be considered. Gunshot residue may be deposited on the face and hair of the shooter or on his clothing. Gunshot residue deposited in these areas will generally be retained longer than gunshot residue of the hands." This, of course, feeds back into the question of why, 8 hours after the shooting, there was plentiful residue on Oswald's hands, but so little residue on his cheek?

 

Edited April 2 by Pat Speer

[Bill Fite]

2 hours ago, Benjamin Cole said:

To be sure, Guinn, or anyone can make mistakes. I made one in 1983 and then another one in 1995, for example. 

LOL - thanks

[Benjamin Cole]

11 hours ago, Pat Speer said:

To my recollection he didn't run tests with any delay beyond 2 1/2 hours to determine how long one could expect a positive result. He decided to test at 2 1/2 hours, and received a positive result. 

From chapter 4f...

(Note: a subsequent study by Vincent Guinn would come to demonstrate that, under laboratory conditions, gunshot residue could be found on suspects as long as 24 hours after a shooting. A similar study by S.S. Krishnan published in 1974 would similarly claim "residue can remain for up to 17h during normal activity, but can be quickly removed by vigorous scrubbing with soap and water." A second study by Krishnan published in 1977 would support this, moreover, by listing a homicide where gunshot residue was found on the hands of a suspect 24 hours after the shooting. While Oswald's odyssey after the shooting was far from what one would expect to find in a laboratory, it was also far less taxing than 17h of normal activity. As a consequence there is nothing in his saga to make one think the residue on his hands, face, and clothes that would be apparent should he have fired a rifle, would have vanished. From May 31 to June 3, 2005, the FBI crime lab held a symposium on gunshot residue analysis. One of the issues discussed was time limits, a time after which the various crime labs present at the symposium would refuse to conduct a test for gunshot residue. According to a summary of this symposium, found on the FBI's website, "Many participants stated that an acceptable cutoff time is 4 to 6 hours after the shooting event, whereas some felt that up to 8 hours was appropriate. Still others were comfortable accepting lifts taken more than 12 hours after the shooting." It was also noted that the FBI's cut-off was 5 hours. A 2006 article on Scienceevidence.com similarly notes that in Saunders v the State of Texas, Aug. 12 2006, "The State’s expert...testified that the time guideline for gunshot residue tests is four hours because of the diminished likelihood of finding the elements necessary for a positive result. The expert testified that it was possible, however, for the test to produce a positive finding even after six or eight hours, but such findings are described as inconclusive. They are not referred to as 'unreliable,' however, because the problem is the likelihood of the evidence disappearing, not the presence of a false positive."

Also

The acceptance of gunshot residue tests of the face has, in fact, in some ways, surpassed even that of gunshot residue tests of the hands. The Elsevier Encyclopedia of Forensic Sciences, published 2000, notes: "In the case of a living shooter, the gunshot residue may be removed by washing the hands; it may also be rubbed off the hands onto clothing. Because of the possibility that gunshot residue may be deliberately removed or inadvertently lost from a shooter's hands other sources of gunshot residue should be considered. Gunshot residue may be deposited on the face and hair of the shooter or on his clothing. Gunshot residue deposited in these areas will generally be retained longer than gunshot residue of the hands." This, of course, feeds back into the question of why, 8 hours after the shooting, there was plentiful residue on Oswald's hands, but so little residue on his cheek?

 

PS--

 

Thanks for your comments and excellent website. 

1. Oh, many reasons, as you know, for GSR (real or false) positives on the outside on LHO's hands. He was in a police car, he was in a police station, where GSR's were common. He handled print materials at the TSBD. There are any number of common items that can lead to false positives. 

Perhaps LHO, fearing a trap, indeed fired at Tippit, and so had GSR on his hands. 

2. For the light dose on LHO's face, perhaps he fired but once, and the TSBD was "exhaling." It was hotter inside the TSBD than outside. and LHO was on an upper floor, meaning the hot air would rise and out the windows. 

Perhaps LHO washed his face at his rooming house, or the Texas Theater. Perhaps, as a CIA asset, LHO knew about and used a GSR-prophylactic while shooting (paper on the face).  Perhaps LHO perspired heavily enough to wash away the GSRs. Eight hours had elapsed, which past the generally accepted time period for accuracy. Guinn's "2.5 hours" comment is curious. 

You say LHO did not take a bathroom break inside the DPD. The guy had a strong bladder perhaps. If he took a bathroom break, would that have been recorded? One wonders why such a delay in applying the paraffin cast. 

All in all, as I say, IMHO, the LHO paraffin test is not dispositive. 

I am still a CT'er.