Combining statistics and chemistry, researchers are challenging the evidence for the lone-gunman theory in the 1963 assassination of United States President John F. Kennedy.

Texas A&M University professor of statistics Cliff Spiegelman recently teamed with former Federal Bureau of Investigation (FBI) agent and forensic scientist William A. Tobin of Forensic Engineering International in Virginia and William D. James, a research chemist with the Texas A&M Center for Chemical Characterization and Analysis (CCCA)and conducted a chemical and forensic analysis of bullets reportedly derived from the same batch as those used by suspected assassin Lee Harvey Oswald to gun down Kennedy on that fateful day at Dealey Plaza.

Will new techniques find new evidence?

Using new compositional analysis techniques not available in the 1960s, the team found that the bullet fragments involved in the assassination are not nearly as rare as previously reported. In addition, their findings show that one of the 10 test bullets from one box analyzed is considered a match to one or more of the five existing assassination fragments, meaning that the matching fragments could have come from three or more separate bullets and, therefore, more than one shooter.

As one of the most traumatic events in U.S. history, the Kennedy assassination sparked a wave of scientific investigation, both immediately after the murder and in the decades since. One such investigation, the 1976 House Select Committee on Assassinations, re-examined the murders of Kennedy and civil rights leader Martin Luther King Jr.

With respect to the Kennedy assassination, the committee concluded, largely on the basis of comparative bullet lead analysis and expert testimony by University of California-Irvine chemist Dr. Vincent P. Guinn, that if there were another shooter or shooters — likely firing from the Grassy Knoll — they missed all limousine occupants.

Ancient history — that is, until Spiegelman got a telephone call in 2004 from Stuart Wexler, a humanities and advanced placement government instructor at Highstown High School in New Jersey, who eventually served as the historian for the team’s paper. Wexler had read online about Spiegelman’s recent work on a National Research Council committee that helped the FBI assess its Compositional Analysis of Bullet Lead (CABL) procedure used as forensic evidence in hundreds of murder cases, including the Kennedy assassination.

"Wexler and a friend of his had bought some bullets of the same type believed to have been used in the Kennedy assassination," Spiegelman recalls. "They were Mannlicher-Carcanos, which were only manufactured in 1954 and are now antiques, mainly because most surviving bullets have been bought up by conspiracy buffs. He was looking for someone to analyze them. I thought it was interesting and that it would be a neat project, so I agreed."

To find a qualified metallurgist and forensic expert, Spiegelman had to look no further than to one of the key figures behind the NRC study in the first place — William Tobin, a decorated FBI agent who in retirement had made a veritable second career out of testifying against his former employer where its evidentiary techniques were concerned.

Spiegelman and Tobin turned to Texas A&M research chemist William James and D. Max Roundhill, former head of the Department of Chemistry at Washington State University and now a consultant in Austin, for the chemical portion of their analysis. Finally, Spiegelman recruited Dr. Simon J. Sheather, professor and head of the Texas A&M Department of Statistics, at the writing stage of the project.

In their study, James analyzed the chemical composition of 30 bullets — 10 from each of three boxes of Mannlicher-Carcano bullets that originated from two of the only four separate lots ever produced. Using a measurement approach similar to Guinn’s, they applied more appropriate standards, such as additional chemical elements beyond those considered at the time, as well as a known quality control procedure. They also analyzed physical samples with a known geometry.

In comparing their data to Guinn’s testimony as well as to NRC report findings, the team determined that many bullets within a box of Mannlicher-Carcano bullets have similar composition, leading them to conclude that two-element chance matches to assassination fragments are not extraordinarily rare — even less rare, considering they came from the same box.

Based on their findings, not to mention the international significance of the Kennedy assassination, Spiegelman and his team say it is "scientifically desirable" for the bullet fragments to be reanalyzed.

Kennedy once said during a Yale commencement address, "The great enemy of the truth is very often not the lie — deliberate, contrived and dishonest — but the myth — persistent, persuasive and unrealistic." Spiegelman claims that "by properly reanalyzing the bullet fragments, our nation has a chance to shatter a myth about the JFK assassination."

"The reanalysis should include at least the seven elements identified in the NRC report, should establish the scientific basis for matching fragments originating from a single bullet, and should address the critically important issues of bullet and source heterogeneity," he adds.

Their findings, which show that evidence used to rule out a second assassin is fundamentally flawed, is available in the paper entitled "Chemical and Forensic Analysis of JFK Assassination Bullet Lots: Is a Second Shooter Possible" here.