The John Tonge Centre, DNA evidence and miscarriages of justice - Part 5

The persuasive power of courtroom science impacts upon juries who tend to regard forensic evidence more highly than they regard witnesses because it seems more objective. Study after study shows that juries put a great deal of faith in the testimony of expert witnesses. A good expert witness can often swing a verdict one way or another. But what happens when the expert lies? What happens when the expert thinks his or her role is to support the case theory espoused by the side that employs him regardless of the results of the tests conducted? Forensic scientists work so closely with police and prosecutors that sometimes their objectivity can be clouded in that pursuit of justice.

Fred Zain was a US West Virginia State Police forensics expert who testified in hundreds of criminal cases. He appeared to know his subject so well that judges, prosecutors, and defence attorneys didn’t question his laboratory results. Juries convicted defendants based on Zain’s testimony even when other evidence conflicted with that testimony or no other incriminating evidence existed. Fred Zain became a forensics expert sought after by prosecutors who wanted to win convictions in difficult cases. He was promoted to Chief of Physical Evidence for the medical examiner in Bexar County, Texas. In that position Fred Zain did for Texas what he had done for West Virginia. He lied.

Zain’s downfall resulted from the 1987 jailing of Glen Woodall who was convicted for multiple felonies including two counts of sexual assault. Zain testified that, based upon his scientific analysis of semen recovered from the victims, “[T]he assailant's blood types ... were identical to Mr. Woodall's”. Woodall received 203 to 335 years imprisonment and the conviction was affirmed on appeal. Independent DNA testing done in a subsequent habeas corpus proceeding established that Woodall could not have been the perpetrator. His conviction was overturned in 1992 and Woodall was freed.

Woodall sued the State of West Virginia for false imprisonment and received US$1 million compensation. This ultimately led to an extraordinary investigation of the entire body of Zain's work ordered by the West Virginia Supreme Court.

The report concluded that the actual guilt of 134 people was substantively in doubt because the convictions were based on inculpatory reports and or testimony by Zain. Nine men have been freed because the remaining evidence offered against them was insufficient for conviction - the expert testimony of Fred Zain alone had put them in prison.

Fred Zain's actions didn’t take place in a vacuum. The conditions that gave rise to his abuses remain in place in other crime laboratories and courtrooms across the US.

In a 21-year career with the US Oklahoma City Police Department forensic chemist Joyce Gilchrist had an unbroken string of positive job evaluations and was Civilian Police Employee of the Year in 1985. The ability to sway juries and win convictions earned Gilchrist the nickname “Black Magic”. She received the nickname in response to her remarkable ability to see evidence other forensic experts could not see.

In the courtroom Gilchrist drew scientific conclusions that others would not approach and turned speculation into scientific fact. In doing so Gilchrist helped the Oklahoma County District Attorney’s office rack up conviction after conviction in addition to sending dozens of prisoners to death row. In 1994 she was promoted from forensic chemist to supervisor.

The reputation of Joyce Gilchrist was shattered in September 2001 when she was fired from the Oklahoma Police Department for laboratory mismanagement, flawed casework analysis and giving false or misleading testimony in criminal cases including some in which she helped send defendants to death row. The forensic scientist’s errors put capital punishment under the microscope in the US.

A preliminary FBI study of eight cases found that in at least five of them Gilchrist had made outright errors or overstepped “the acceptable limits of forensic science”. Gilchrist got convictions by matching hair samples with a certainty other forensic scientists found impossible to achieve. She was also accused of withholding evidence from the defence and failed to perform tests that could have cleared defendants.

Gilchrist’s testimony helped put Robert Lee Miller Jr in prison for 11 years for a murder he never committed. In 1998 Miller was released from death row based on the results of independent DNA tests. In Miller’s case the forensic chemist linked him to the rape and murder of two elderly women by comparing hairs under a microscope. She eliminated another suspect, Ronald Lott, by the same hair comparisons.

The subsequent DNA test of semen from the crime scene not only freed Miller from death row but pointed to Lott as the perpetrator. Lott was arrested on two counts of first-degree murder. In that case Gilchrist’s testimony implicated an innocent man and helped put him on death row and excluded Lott as a suspect until independent DNA testing linked him to the crime.