Better Forensic Science could reveal more about the JFK assassination

[Jon Banks]

Texas A&M Today:

Two Shooters? Texas A&M Statistician Says Better Forensic Science Can Reveal More About The JFK Assassination

Popular television shows such as the ?Law & Order,? ?CSI? and ?NCIS? franchises glorify forensic science as a magical, near-flawless tool for identifying criminals. Not surprisingly, Hollywood?s depiction of forensic science needs a reality makeover.

The ?CSI effect? is well-documented. As long ago as 2009, scientists with the National Research Council noted that no forensic method (except for nuclear DNA analysis) can reliably and consistently connect evidence to a specific individual or source. More recently, President Obama?s Council of Advisors on Science and Technology reported that pattern-matching forensic procedures are unreliable. The Innocence Project has exonerated many hundreds of wrongfully convicted people, and bad forensic science was found to be a contributing factor in about half of the original cases.

These problems are not new. Six years before the National Research Council?s 2009 report, I was on a panel of the council that looked at a particular forensic technique used to match bullets found at crime scenes (typically murders) to bullets found in a suspect?s possession. That procedure, called comparative bullet lead analysis, was first used in the investigation into the assassination of President John F. Kennedy in 1963. What the panel found 40 years after the event contradicted the FBI?s analysis of the evidence at the time, and caused the bureau to stop using the technique altogether...

On the Bullet analysis:

...we wanted to test Guinn?s claim that each bullet was chemically distinguishable from each other. If that wasn?t true, we also hoped to identify whether any of our bullets matched any of the bullet fragments from the Kennedy assassination investigation.

We analyzed 30 bullets, and found that all but one matched at least one of the other bullets in the batch. The one that didn?t match any others we tested did actually match with fragments taken from Kennedy?s head. This meant that Guinn was incorrect: Individual bullets did not have uniquely identifiable chemical components. In fact, the number of bullets involved could have been as few as the two Guinn claimed, or as many as five. Given the congressional conclusion that there had been four shots, it remains possible that Oswald was not the only shooter who hit the president ? and that Oswald may not have fired the fatal shot.

Flawed forensic science had misled not only the congressional committee investigating the assassination, but also the entire nation. Our demonstration captured a lot of public attention. But more importantly, it suggests that a deeper understanding of truth can come from improving forensic science. This is useful as scholars examine newly released John F. Kennedy assassination documents, and as criminal trials around the country seek justice for victims and accused alike...

https://today.tamu.edu/2017/12/07/two-shooters-texas-am-statistician-says-better-forensic-science-can-reveal-more-about-the-jfk-assassination/

[Jon Banks]

So 1-in-30 bullets "matched" the properties of the head-shot fragments?

    "This finding means that the bullet fragments from the
     assassination that match could have come from three
     or more separate bullets. If the assassination fragments
     are derived from three or more separate bullets, then a
     second assassin is likely."

So--based on the study--there's a 1-in-30 chance that two assassins happened to fire a "matched" bullet into Kennedy's head (the only known source of fragmentation) at the same moment.

More focus on the word "could" and less on "likely".

The study didn?t Prove there was more than one Shooter.

It proved that multiple shooters could not be ruled out based on Lead analysis (as claimed in the past by Dr Vincent Guinn).

[Jon Banks]

OK. You had highlighted: it remains possible that Oswald was not the only shooter who hit the president ? and that Oswald may not have fired the fatal shot.Their study demonstrated a 29/30 chance that the lead fragments Guinn said matched came from an individual bullet.

Their study proved that Guinn?s conclusion that all bullets and fragments came from the same rifle was total BS.

Washington Post:

?The "evidence used to rule out a second assassin is fundamentally flawed," concludes a new article in the Annals of Applied Statistics written by former FBI lab metallurgist William A. Tobin and Texas A&M University researchers Cliff Spiegelman and William D. James.?

?Now-deceased University of California at Irvine chemist Vincent P. Guinn. told the committee that he used bullet lead analysis to conclude that the five bullet fragments recovered from the Kennedy assassination scene came from just two bullets, which were traced to the same batch of bullets Oswald owned. Guinn's conclusions were consistent with the 1960s Warren Commission Report that found Oswald had acted alone. The House assassinations committee, however, concluded that Oswald probably was part of a conspiracy and that it was possible a second shooter fired one shot that missed the president.

Tobin, Spiegelman and James said they bought the same brand and lot of bullets used by Oswald and analyzed their lead using the new standards. The bullets from that batch are still on the market as collectors' items.

They found that the scientific and statistical assumptions Guinn used -- and the government accepted at the time -- to conclude that the fragments came from just two bullets fired from Oswald's gun were wrong.

"This finding means that the bullet fragments from the assassination that match could have come from three or more separate bullets," the researchers said. "If the assassination fragments are derived from three or more separate bullets, then a second assassin is likely," the researchers said. If the five fragments came from three or more bullets, that would mean a second gunman's bullet would have had to strike the president, the researchers explained.?

http://www.washingtonpost.com/wp-dyn/content/article/2007/05/16/AR2007051601967.html

[Jon Banks]

I believe all they're raising is doubt.

Broadly yes. Absent solid evidence of multiple shooters (a second rifle to analyze for example) the best they can say is the Bullet evidence doesn?t rule out multiple shooters. 

They have said Forensic Science in general isn?t like CSI TV shows. Often times forensic evidence can be interpreted more than one way. Prosecutors and Defense Lawyers can cherry pick or pick apart Forensic Evidence to support their cases.

They have more confidence in DNA analysis than other forms of Forensic Analysis.