Lee Harvey Oswald was linked to the Mannlicher-Carcano rifle alleged to have been used to shoot President Kennedy by the hair and fiber analysis of FBI expert Paul Stombaugh. The Warren Commission’s final report drew conclusions from Stombaugh’s testimony that buttressed assertions about Oswald’s guilt, particularly the association between hair and fiber evidence allegedly tying Oswald to the rifle.
The Commission considered Stombaugh’s testimony of “probative value,” the report stated.
But a devastating recent study by the Justice Department and the FBI shows that close analysis of cases involving hair and fiber testing raises grave concerns about the role of similar scientific testimony by law enforcement experts in criminal convictions.
“Justice Department and FBI have formally acknowledged that nearly every examiner in an elite FBI forensic unit gave flawed testimony in almost all trials in which they offered evidence against criminal defendants over more than a two-decade period before 2000,” the Washington Post reported on April 18.
“The review confirmed that FBI experts systematically testified to the near-certainty of ‘matches’ of crime-scene hairs to defendants, backing their claims by citing incomplete or misleading statistics drawn from their case work,” the Post’s Spencer Hsu reported.
“In reality, there is no accepted research on how often hair from different people may appear the same. Since 2000, the lab has used visual hair comparison to rule out someone as a possible source of hair or in combination with more accurate DNA testing.”
One University of Virginia law professor quoted by the Post described the results of the study as a “mass disaster.” The unfounded science has remained uncorrected because courts rely on outdated precedents that admitted scientifically invalid testimony at trial.
A 96 percent error rate
The Post report stated that the results of the first 268 cases examined showed that FBI testimony was fundamentally flawed in 257 of those cases — a “stunning” 96 percent of the total.
With the proliferation of “Crime Scene Investigation” TV shows detailing police procedures and the key importance of the gathering and analysis of forensic evidence, public awareness of technical demands in these areas has increased.
So has scientific scrutiny. A 2009 report for the Department of Justice by the Committee on Identifying the Needs of the Forensic Sciences Community, entitled “Strengthening Forensic Science in the United States: A Path Forward,” reviewed issues involving forensic evidence with an eye toward scientific corroboration of methods and analysis. Hair and fiber evidence were among the topics reviewed in the study.
The report concluded that hair and fiber sample analysis for purposes of admissibility in criminal trials was characterized by “imprecision” and a lamentable lack of consensus within the scientific community, which is a threshold test for admissibility.
As a science adviser to President Obama recently wrote in the New York Times, it is time to “Fix the Flaws in Forensic Science.”
What Stombaugh said
What does the new scientific research tell us about the Warren Commission’s findings?
Stombaugh’s 1964 testimony linked Oswald to the rifle by concluding that certain hair and fiber samples could be associated with Oswald and with a blanket found in the garage of his wife’s Irving, Texas residence.
Stombaugh was careful to qualify some of his key opinions. He said he was “unable to render an opinion that the fibers which he found in the bag had probably come from the blanket.” At other times he said, “All I would say here is that it is possible;” and “the possibility exists, these fibers could have come from this blanket.”
The Warren Commission report omitted most of those qualifications in asserting the “probative value” of Stombaugh’s testimony, which was said to be “strong evidence” that the rifle was “most probably” linked recently to Oswald’s shirt.
“The Commission was unable to reach any firm conclusion as to when the fibers were caught in the rifle….” the report stated. “The Commission was able to conclude, however, that the fibers most probably came from Oswald’s shirt. This adds to the conviction of the Commission that Oswald owned and handled the weapon used in the assassination.”
What we know now
Advances in the scientific methods of analyzing such evidence over the decades since the Warren Commission’s Report have undermined the strength of the hair and fiber evidence inculpating Oswald.
The recent revisions to the state of the art of hair and fiber analysis provide cautionary lessons. The continued withholding of still-classified documents involving Oswald and related matters should serve to belay hasty conclusions about the exact nature of his involvement. The progress in analysis of various types of evidence (acoustics / recordings, documents) should provide impetus for declassification.
In short, the evolution of scientific consensus may lead to new insights into the evidence in the JFK case. In some instances, the public’s skepticism about the case against Oswald has been shown to be well-founded. An open mind and dispassionate discussion of the elements of the case against Oswald will promote elucidation of the true facts, which we would hope to also evolve.
Patrick McCarthy is an attorney in Pleasanton, California