Flaws In Forensic Science
Crime Labs Need Improvement
The quality of the labs is criminal; government must invest in personnel and facilities.
In their examination of the criminal convictions of 62 men who were later exonerated by DNA evidence, Barry Scheck, Peter Neufeld, and Jim Dwyer concluded that a third of the cases involved “tainted or fraudulent science.” Although in some cases rogue experts were directly to blame, a much larger problem exists: The forensics profession lacks a truly scientific culture—one with sufficient written protocols and an empirical basis for the most basic procedures. This results in an environment in which misconduct can too easily thrive. Stated another way, forensic science needs more science.
On an individual level, one of the most notorious cases involved Fred Zain, the chief serologist of the West Virginia State Police Crime Laboratory. A judicial report found that Zain committed many acts of misconduct over 10 years, including overstating the strength of results, reporting inconclusive results as conclusive, repeatedly altering laboratory records, grouping results to create the erroneous impression that genetic markers had been obtained from all samples tested, and failing to report conflicting results. In reviewing the report, the West Virginia Supreme Court spoke of “shocking and egregious violations” and the “corruption of our legal system.”
On a systemic level, perhaps the best example is the Federal Bureau of Investigation (FBI) laboratory, considered to be the country’s premier crime lab. A 1997 Inspector General’s report on the lab found scientifically flawed testimony, inaccurate testimony, testimony beyond the competence of examiners, improper preparation of laboratory reports, insufficient documentation of test results, scientifically flawed reports, inadequate record management and retention, and failures of management to resolve serious and credible allegations of incompetence. The report’s recommendations are revealing because they are so basic. They include: seeking accreditation of the laboratory by the American Society of Crime Laboratory Directors/Laboratory Accreditation Board (ASCLD/LAB); requiring examiners in the explosives unit to have scientific backgrounds in chemistry, metallurgy, or engineering; mandating that each examiner prepare and sign a separate report instead of a composite report without attribution to individual examiners; establishing a review process for analytical reports by unit chiefs; preparing adequate case files to support reports; monitoring court testimony in order to preclude examiners from testifying to matters beyond their expertise or in ways that are unprofessional; and developing written protocols for scientific procedures. In short, the report called for scientific management.
More than a decade ago, molecular biologist Eric Lander, who served as an expert witness in one of the first court cases involving DNA evidence, noted: “At present, forensic science is virtually unregulated, with the paradoxical result that clinical laboratories must meet higher standards to be allowed to diagnose strep throat than forensic labs must meet to put a defendant on death row.” Since that time, there have been a number of voluntary attempts to improve crime laboratories, such as the accreditation process of the ASCLD/LAB. Nevertheless, except for New York, Texas, and Oklahoma, there is no mandatory accreditation. A similar situation exists with death investigation agencies accredited by the National Association of Medical Examiners. Although 40 medical systems have been accredited, they cover only 25 percent of the population. In addition, accreditation rates are low for practicing forensic scientists, even though forensic certification boards for all the major disciplines have been in existence for more than a decade.
Although it is not the only reason, lack of funding is a major contributing factor to these failures. Meeting accreditation and certification standards costs money, and crime labs have been chronically shortchanged. In 1967, President Johnson’s Crime Commission noted that, “The great majority of police department laboratories have only minimal equipment and lack highly skilled personnel able to use the modern equipment now being developed.” In 1974, President Nixon’s Crime Commission commented: “Too many police crime laboratories have been set up on budgets that preclude the recruitment of qualified, professional personnel.” Twenty years later, an investigation of Washington state crime labs revealed that a “staggering backlog of cases hinders investigations of murder, rape, arson, and other major crimes.” At any time, “thousands of pieces of evidence collected from crime scenes sit unanalyzed and ignored on shelves in laboratories and police stations across the state.” A USA Today survey in 1996 reached the same conclusion: “Evidence that could imprison the guilty or free the innocent is languishing on shelves and piling up in refrigerators of the nation’s overwhelmed and underfunded crime labs.” In one case reported by the newspaper, a suspected serial rapist was released because it was going to take months to get the DNA results needed to prove the case. Weeks later, the suspect raped his fourth victim as she slept in her home. When the DNA tests finally came back—18 months after samples first went to the lab—a jury convicted the suspect of all four rapes.
It is clear, then, that to improve scientific evidence in criminal cases, the nation’s crime laboratories must be improved. They need to be funded so they can be accredited and their examiners certified. The lessons learned from the DNA admissibility wars should not be forgotten. Valid protocols and rigorous proficiency testing are important. As the FBI’s leading DNA expert later conceded, there were significant problems when DNA evidence was first introduced in court: “The initial outcry over DNA typing standards concerned laboratory problems: poorly defined rules for declaring a match; experiments without controls; contaminated probes and samples; and sloppy interpretation of autoradiograms. Although there is no evidence that these technical failings resulted in any wrongful convictions, the lack of standards seemed to be a recipe for trouble.” Moreover, the National Research Council’s (NRC’s) first of two reports on DNA observed: “No laboratory should let its results with a new DNA typing method be used in court, unless it has undergone such proficiency testing via blind trials.” The same types of standards now required for DNA testing should apply to all forensic examinations.
The need for basic research
Another critical issue is the lack of basic scientific research. Many forensic techniques were developed in crime labs, not research labs, and they gained judicial acceptance before the demanding standards of the Supreme Court’s Daubert decision were in place. As recent cases have demonstrated, there is an embarrassing lack of empirical research on well-accepted techniques such as fingerprinting, firearms identification, and bite-mark comparisons.
Hair comparison evidence illustrates both the lack of empirical research and the misuse of expert testimony. Most courts have upheld the admissibility of hair comparison evidence. After Daubert was decided, however, the district court in Williamson v. Reynolds, a habeas corpus case, took a closer look at this type of evidence. In the case, an expert testified that hair samples were “microscopically consistent,” explaining that “hairs are not an absolute identification, but they either came from this individual or there is [or] could be another individual somewhere in the world that would have the same characteristics to their hair.” The district court noted that the expert did not explain which of the approximately 25 characteristics were consistent, any standards for determining whether the samples were consistent, how many persons could be expected to share this same combination of characteristics, or how he arrived at his conclusions. Moreover, the court professed that it had been “unsuccessful in its attempts to locate any indication that expert hair comparison testimony meets any of the requirements” of Daubert. The court further observed: “Although the hair expert may have followed procedures accepted in the community of hair experts, the human hair comparison results in this case were, nonetheless, scientifically unreliable.” Finally, as is often the case, the prosecutor exacerbated the problem by telling the jury during his closing argument that a match existed. Even the state court misinterpreted the evidence, writing that the “hair evidence placed [petitioner] at the decedent’s apartment.” The district court decision was subsequently reversed because due process, not Daubert, provided the controlling standard for habeas review. The accused, however, was later exonerated by exculpatory DNA evidence, and as Scheck and his colleagues observe, “The hair evidence was patently unreliable.”
In another case, the expert testified that the crime scene hair sample “was unlikely to match anyone” other than the defendant, Edward Honaker, who had been charged with rape. This conclusion was a gross overstatement. At best, the expert could have testified that the crime scene hairs were “consistent with” the defendant’s exemplars, which means that they could have come from Honaker or thousands of other people. We simply have no idea how many other people have the same characteristics. Honaker spent 10 years in prison before being exonerated by DNA analysis.
Roger Coleman was executed in 1992 for a slaying in rural Virginia. The same expert who had testified against Honaker also testified against Coleman, and in the same manner. The U.S. Supreme Court ruled that a lawyer’s mistake in filing Coleman’s state collateral appeal one day late precluded federal habeas review. Serious questions about Coleman’s innocence have since been raised, and the prosecution’s use of the hair evidence was, to say the least, suspect. While conducting research for his book on the Coleman case, John Tucker interviewed the trial judge, who said he thought the expert’s testimony about the comparison of the pubic hairs had the most powerful impact on the jury. It was, the judge said, the first and only testimony that seemed to tie Coleman to the murder. As Tucker correctly notes: “A finding of consistency is highly subjective, and experts may and often do disagree about such a finding.” Tucker describes the testimony as follows: “Nor did [the expert] compare the pubic hairs found on Wanda [the victim] with anyone other than Coleman and Wanda herself—not even her husband Brad. Nevertheless, when he asserted that he had made a comparison of those hairs with Roger’s pubic hair, and that the hairs were ‘consistent’ with each other, meaning, he said, that is was ‘possible, but unlikely’ that the hairs found on Wanda could have come from anyone other than Roger Coleman, the jurors exchanged glances and settled back in their seats.”
Only the federal government, specifically the FBI and the National Institute of Justice, has the resources to fund the needed research on forensic science. The actual research, however, should be done by independent organizations such as the NRC, which in addition to its DNA reports has conducted studies on voiceprints, polygraph tests, and bullet lead comparisons.
As DNA evidence has demonstrated, expert testimony based on scientific and technical knowledge is often better than other types of evidence commonly used in criminal trials. The danger of eyewitness misidentification has long been recognized and is the single most important factor in wrongful convictions. The unreliability of jailhouse snitches also comes as no surprise. The use of confessions that later turn out to be false has also been documented. Indeed, in Escobedo v. Illinois, the Supreme Court observed: “We have learned the lesson of history, ancient and modern, that a system of criminal law enforcement which comes to depend on the ‘confession’ will, in the long run, be less reliable and more subject to abuses than a system which depends on extrinsic evidence independently secured through skillful investigation.” Nevertheless, the advantages of scientific and technical evidence depend on its reliability, and that turns on whether forensic science is truly a scientific endeavor.
Edward Connors, Tom McEwen, Thomas Lundregan, and Neal Miller, Convicted by Juries, Exonerated by Science: Case Studies in the Use of DNA Evidence to Establish Innocence After Trial (Washington, D.C.: U.S. Department of Justice, 1996).
Max Houch and Bruce Budowle, “Correlation of Microscopic and Mitochondrial DNA Hair Comparisons,” Journal of Forensic Science 47 (2002): 964—966.
Eric S. Lander and Bruce Budowle, “DNA Fingerprinting Dispute Laid to Rest,” Nature 371 (Oct. 27, 1994): 735—735.
Eric S. Lander, “DNA Fingerprinting On Trial,” Nature 339 (1989): 501—505.
Office of Inspector General, U.S. Department of Justice, The FBI Laboratory: An Investigation into Laboratory Practices and Alleged Misconduct in Explosives-Related and Other Cases (Washington, D.C.: April 1997).
“President’s Editorial—The Changing Practice of Forensic Science,” Journal of Forensic Science 47 (2002): 437—438.
Barry Scheck, Peter Neufeld, and Jim Dwyer, Actual Innocence: Five Days to Execution and Other Dispatches from the Wrongly Convicted (New York: Doubleday, 2000).
John Tucker, May God Have Mercy: A True Story of Crime and Punishment (New York: Dell, 1998).
Paul C. Giannelli (firstname.lastname@example.org) is the Weatherhead Professor of Law at Case Western Reserve University in Cleveland, Ohio.