UCI Professor William Thompson Reveals How DNA Evidence Was Abused and Manipulated for Wrongful Conviction of Josiah Sutton

Irvine, Calif., April 7, 2003 -- In 1999, a Houston teenager named Josiah Sutton was convicted of rape and sentenced to 25 years in a Texas penitentiary. Then last month, the same evidence that convicted Sutton was used to set him free. It's a reversal of justice that has shaken faith in the Texas judicial system and will likely lead to more overturned convictions in the state.

Among those celebrating this prisoner's release is the DNA expert whose analysis exonerated Sutton.

William Thompson, a UC Irvine professor who studies scientific evidence, became involved with the case at the request of investigative reporters from a Houston television station. Perhaps best known as a member of O.J. Simpson's defense "dream team," Thompson was asked to study eight cases that the Houston criminal justice system successfully prosecuted by primarily relying on DNA evidence. He found serious shortcomings in all of the cases. "Worst of all, in some cases, it appeared that DNA evidence had been manipulated to guarantee convictions instead of justice," Thompson said.

Now the Houston police department's crime laboratory has been shut down and is being investigated for criminal wrongdoing. "DNA has the potential to do amazing good, but it's not always definitive," he said. "The Sutton case reveals some of the problems that face the justice system nationwide."

Inside the Josiah Sutton Case

Thompson learned of the crime lab problems last fall after being approached by CBS affiliate KHOU-TV. Reacting to rumors about the department, an investigative news team had obtained copies of crime lab records and court documents through the state public records act. Needing assistance in evaluating the information, they asked Thompson to review the lab work and provide expert analysis in seven criminal cases. It didn't take long for him to draw a conclusion.

"It was the worst laboratory work I have ever seen," Thompson said. "They failed to run essential scientific controls, failed to document their work adequately and engaged in a variety of practices that enhanced the chances of error." He also found that lab analysts reported results in a misleading manner and overstated the statistical significance of the findings. In at least two instances, the lab's conclusions were inconsistent with underlying scientific data.

After Thompson's scathing critique was aired on television, an audit was performed of the Houston crime lab. In January, the police suspended operations in the DNA/serology section of its laboratory. The news team asked Thompson to review the DNA evidence used against Josiah Sutton. This included semen samples collected from the rape victim and from the backseat of the victim's automobile, where the rape occurred.

The crime lab had analyzed the samples and provided testimony critical for the verdict. Said Thompson, "The crime lab's testimony left the impression that the DNA evidence uniquely and definitively identified Sutton as one of the rapists."
But as Thompson found after reviewing the records, the lab's tests were far from conclusive. "The police could have picked any two black men off the street and the chances were one in eight that one of them would match the sample as well as Sutton."

Then Thompson made an even more important discovery key to freeing Sutton.

Freeing Josiah Sutton

When he analyzed the information reported by the lab regarding the backseat semen stain, Thompson realized the crime lab had incorrectly reported that it contained a mixture of DNA from Sutton, the victim and an unknown man. Thompson found that the semen from this stain came from a single man and was not a match for Sutton. With this discovery, Thompson could subtract the DNA profile of the one rapist from the sample collected from the victim, isolating the DNA profile of the second man.

"It was a revelation," Thompson said. "Clearly, the profile of the second man did not match Sutton."

When KHOU-TV reported Thompson's conclusions, Harris County's district attorney agreed to additional DNA testing. Using new test procedures more definitive than those used by the police, a private laboratory confirmed that semen obtained from the victim was not a match with Sutton. The district attorney is now reviewing all cases in which DNA evidence contributed to a conviction and plans to have DNA evidence in a number of cases re-tested at independent laboratories. There has also been a call to "cease and desist" any executions in the relevant cases.

"What I saw in the Houston lab was incompetence," Thompson said. "The analysts presented themselves as scientists, but they don't fundamentally understand what they are doing. They make up for their incompetence with bias -- distorting ambiguous findings to fit the prosecutor's theories. Prosecutors thought the lab was doing fine because they kept getting what they wanted."

Now as he looks at other cases in Houston for the news team, he believes more men may be freed from Texas prisons. "Josiah Sutton is just the tip of a Texan iceberg," he said. "In Texas, defense lawyers are so poorly funded and so hobbled by procedural barriers, they have been unable to catch serious problems. There are probably many cases similar to this."

Peter Neufeld, who co-directs the Innocence Project at Cardozo Law School in New York, agreed. "Thompson's work is particularly important because he has identified a crack in the Houston Police crime laboratory, which has been the nation's No. 1 pipeline to execution," he said. Neufield also points out that the Sutton case is one of only two cases where DNA evidence also figured in the false conviction. "What happened in Houston could have important ramifications for the broader debate about the fairness of capital punishment."

Defending O.J. Simpson

A UCI criminology professor for 20 years, Thompson is one of the nation's leading authorities on the use -- and abuse -- of DNA evidence in the courtroom. An attorney, he is trained in psychology as well and is interested in jurors' ability to evaluate scientific and statistical data. Most famously, he was one of 12 lawyers that represented O.J. Simpson during his murder trial.

According to Thompson, the Simpson and Sutton case have similarities. While the Simpson case involved a wealth of DNA evidence -- including the notorious blood trail leading from the crime scene as well as the "famed" bloody glove -- at issue was the competence of the Los Angeles crime laboratory. For example, while collecting and handling DNA samples during the Simpson case, a lab technician spilled a vial of Simpson's blood on his fingers right before handling the glove that later was found to contain traces of Simpson's DNA. "Although the technical difficulties and discrepancies with the DNA evidence in the Simpson case were not well explained or reported by the media, they did provide a basis on which a reasonable jury could have rejected much of the evidence," Thompson said.

As a professor at UCI, Thompson's research has focused on the use of forensic DNA tests and other mathematical and scientific evidence in jury trials. He also has studied the use in trials of hearsay and character evidence and the testimony of children.