With Eye Toward Justice, Texas A&M Prof Takes Statistics To The Courtroom
COLLEGE STATION, Oct. 30, 2012 – Cliff Spiegelman keeps a thank-you note from a client, along with a retainer for his professional services on that effort, a $1 bill. That’s more than the distinguished professor in the Texas A&M University Department of Statistics often gets for his public service. But his mission to improve forensic science in the criminal justice system isn’t about money.
“I couldn’t sleep at night, knowing that I didn’t stand up and do the right thing,” Spiegelman said from his office, where the United States Constitution, in four-poster-sized frames, looms over his desk.
Spiegelman makes a few out-of-state trips a year to testify in cases in which he believes the forensic science is flawed. He often works with the Innocence Project, the national non-profit legal clinic dedicated to exonerating wrongfully convicted people through DNA testing and other post-verdict methods.
But before Spiegelman agrees to take on a trial-level case, he has a prerequisite: He has to be convinced there’s a chance the defendant is innocent.
“My conversations with the defense lawyers go something like this: If your guy confessed to you and you believe him, please find someone else,” Spiegelman said.
Relying on his statistics expertise, Spiegelman was an ardent opponent of a method of forensic testing called Comparative Bullet-Lead Analysis (CBLA), which partly through his work, the FBI discredited in 2007. The abandoned technique, which used chemistry to link bullets from a crime scene to those owned by a suspect, was first used following the 1963 assassination of President John F. Kennedy.
Spiegelman admits it’s often been a challenge bringing statistics to the criminal justice system, where the concept of stare decisis — the legal reverence to precedence — makes changes to the system difficult. But, he says, it’s a mistake not to embrace statistics in the courtroom.
“There’s always the chance of error,” he said. “So, for instance, if a hair from the defendant is similar to one found at the crime scene, the issue is, what is the frequency of hairs that are similar in the general population? Ninety percent? Ten percent? One percent? The relevance of the evidence is based in part on how common it is. And that’s a statistical issue.”
Spiegelman’s interest in statistical forensics was sparked in 2002, when, because of his expertise in statistics in chemistry, he was appointed to serve on a National Research Council (NRC) panel to study bullet lead evidence. During the meetings, he would step out to inject himself in the stomach with a high dose of interferon as part of a difficult chemotherapy treatment.
Spiegelman’s doctor gave him a 50 percent chance of living. Instead of quitting the panel to focus on his treatment, Spiegelman immersed himself in the work with the stark realization that it could be his last professional act.
The treatment was a success, and while he overcame the threat to his life, his passion for statistical forensics remained.
In 2008, Spiegelman was a co-recipient of a prestigious national award for leading a team that published a paper finding that forensic evidence used to rule out the presence of a second shooter in President Kennedy’s slaying was fundamentally flawed. He shared the American Statistical Association’s 2008 Statistics in Chemistry Award with Simon Sheather, professor and head of the Texas A&M Department of Statistics, William D. James, a researcher with the Texas A&M Center for Chemical Characterization and Analysis (CCCA), and three other co-authors.
The paper showed that the bullet fragments involved in the assassination were not nearly as rare as previously thought, and that the likelihood that all the fragments didn’t come from the same batch of bullets also was greater than previously thought. Bullet matches were found to be much more likely than was indicated in testimony presented before the House Select Committee on Assassinations, which was formed in 1976 to investigate the assassinations of President Kennedy and Rev. Martin Luther King Jr., as well as other shootings with similar national prominence.
Spiegelman doesn’t take a stance on whether he believes presumed assassin Lee Harvey Oswald acted alone. That’s beyond his scope of examining the quality of the CBLA forensic science, he says. And though he often receives letters because of his assassination research — like the one from a clergyman who says he delivered last rites to a condemned mobster in Central America who said the mob was involved, and the Aggie who claims to have found the second shooter’s rifle in a hotel room the day after the assassination — he stresses that he’s not a Kennedy assassination buff.
But Spiegelman says the Kennedy case is the ultimate example: If the science could be wrong in a case with intense public interest and with the government having all the resources it needed, then it certainly could — and has often been — wrong in much more low-profile cases.
Spiegelman says the discrediting of CBLA as an unreliable procedure was the result of a years-long, multi-pronged effort. One of his co-authors on the Kennedy paper — William A. Tobin, a former chief metallurgist for the FBI — had been raising concerns about the technique since the 1990s, leading to the convening of the NRC panel that studied the technique. But it wasn’t until national media such as CBS’ 60 Minutes and The Washington Post started reporting on CBLA in 2007 that the FBI officially announced it would permanently discontinue use of the procedure.
“It takes a village to take down bad forensic science,” Spiegelman said.
Spiegelman was a founder within the statistical sciences of the field of chemometrics, the science of using data to extract information from chemical systems. He also is a senior research scientist at the Texas A&M Transportation Institute, the state of Texas’ transportation research agency. He joined the Texas A&M Department of Statistics in 1987 as an associate professor and became a distinguished professor in 2009.
For more about Texas A&M Statistics, visit http://www.stat.tamu.edu.
To learn more about the Innocence Project, go to http://www.innocenceproject.org.