Reasonable Doubt
Can Crime Labs be Trusted?
A joint investigation by CNN and the Center for Investigative Reporting examines the lack of standards, quality controls and training at many of the nation's forensic laboratories and raises serious doubts about some forensic scientists.
The
Labs
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Arnold Melnikoff Arnold Melnikoff was the manager of Montana's state crime laboratory who testified in the 1987 trial of Jimmy Ray Bromgard, who was convicted of raping an 8-year-old girl. Melnikoff said that hairs taken from Bromgard and hairs from the crime scene were "almost indistinguishable," and there was a 1 in 10,000 chance that Bromgard was not the rapist. In 2002, DNA testing proved Bromgard's innocence and there have been questions about Melnikoff's work in other cases. Two other convictions have been overturned in Montana. Melnikoff was working for Washington State Patrol, but was dismissed last year based on the patrol's finding that his testimony in Montana was erroneous. He is appealing his dismissal and declined to speak to CNN. His attorney told CNN that Melnikoff admits some of his statistical calculations may have been off, but that he is confident in the rest of his work. |
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Joyce Gilchrist Joyce Gilchrist collected and analyzed evidence for the Oklahoma City Police for 21 years before her mistakes were caught. After a judge criticized her testimony, FBI and internal police reviews turned up problem after problem with Gilchrist's work. Her misidentification of hairs helped send Jeffrey Pierce to prison. Pierce is one of at least three men whose convictions have since been overturned, including one who was on death row. Gilchrist was fired in 2001, but hundreds of cases spanning two decades have to be reviewed. Gilchrist declined to speak with CNN, but her attorney maintains she did nothing wrong. |
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Fred Zain Fred Zain was a chemist at West Virginia's state crime lab for 12 years. But in 1993, a report by the West Virginia Supreme Court discredited his work, finding that "any testimonial or documentary evidence offered by Zain at any time in any criminal prosecution should be deemed invalid, unreliable and inadmissible." False laboratory work by Zain helped put at least six men in prison erroneously in two states. He was indicted for false testimony, but died before he could be brought to trial. |
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Jacqueline Blake Last year, a report by the Justice Department's inspector general found that FBI lab employee Jacqueline Blake failed to complete a critically important test in 90 cases. The test, which detects whether or not a DNA sample has been contaminated, is called a negative control. Blake also "falsified her laboratory documentation to conceal" her improper work, according to the inspector general's report. The FBI declined to discuss the Blake case with CNN. Retests of Blake's work did not turn up any results that were wrong. She resigned from the FBI in 2002. Last year she pleaded guilty in federal court to making false statements in her lab reports. |
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Houston Police crime lab DNA unit In 2002, reporters with KHOU asked professor William Thompson, an expert in scientific evidence, to review a handful of lab reports from the DNA unit of the Houston Police Department's crime lab. Defense attorneys, who had become suspicious of the accuracy of the lab's reports, tipped off the reporters. After KHOU's reports were broadcast, the police department sought an external audit of the DNA unit. After the audit, the unit was closed and the Harris County District Attorney's office is retesting DNA evidence in almost 400 cases. One of the first retests exonerated Josiah Sutton, who was wrongly convicted of rape and had been in prison for four and a half years. So far, the retesting has confirmed most -- but not all -- of the original results. |