Testimony of Robert Perry on behalf of the New York Civil Liberties Union before The New York State Assembly Committee on Codes and the Committee on Correction on Legislation addressing the state's DNA database
(Note: Testimony given on this subject by Queens College Professor of Sociology Harry Levine, an expert on racial disparities in arrests for marijuana possession in New York City, is available here (PDF).)
My name is Robert Perry. I am the legislative director with the New York Civil Liberties Union (NYCLU), on whose behalf I submit this testimony today.
At a meeting of the Assembly democratic conference during the 2006 legislative session, a member reportedly objected to legislation that would further expand the state's DNA database. As the meeting adjourned, the Assembly member who had voiced his concerns about the bill was approached by a colleague who asked, "What, are you anti-science?"
The proponents of forensic DNA testing have been highly effective in selling the general public – and, perhaps most notably, lawyers and legislators -- on the notion that DNA evidence is virtually infallible. To be sure, under optimum circumstances DNA evidence is an extraordinarily precise forensic tool. However, the collection and analysis of DNA evidence is a human endeavor; it is therefore susceptible to human fallibility – and this scientific fact has not yet been introduced into the debate over the size and scope of the state's DNA databank.
DNA evidence is not infallible
When DNA analysis is conducted with accuracy and precision, the results can be highly probative in making determinations of guilt or innocence in criminal matters. But the error rate is not zero. False positives do occur. Errors are a function of many factors, including the degradation of the DNA sample.
Even when a DNA sample is of good quality, the judgment of the lab technician enters into the analysis of the sample and the reporting of the results. What's more, the collection, processing and handling of DNA samples introduces many opportunities for error. This has led to a rash of DNA testing errors in labs throughout the country due to cross-contamination and mislabeling of samples.
Professor William C. Thompson, J.D., Ph.D. (Department of Criminology, Law & Society at the University of California, Irvine) published an article in 2006 that documented an extraordinary number of problems related to forensic DNA evidence. For example:
The Houston Police Department shut down the DNA and serology section of its crime laboratory in early 2003 after a series of investigations found serious deficiencies in the lab's procedures. Two men who had been falsely incriminated by botched lab work were released after subsequent DNA testing proved their innocence.
In Virginia, post-conviction testing in the high-profile case of Earl Washington, Jr., contradicted DNA tests on the same samples that had been conducted earlier by the State Division of Forensic Sciences. (Washington had been wrongly convicted; he was hours from execution when the lab errors were confirmed.) An independent investigation concluded that the state lab had botched the DNA analysis of the case, failing to follow proper procedures and misinterpreting the lab's own test results.
An investigation conducted in 2004 by the Seattle Post-Intelligencer documented twenty-three DNA testing errors in serious criminal cases that had been handled by the Washington State Patrol laboratory.
The Illinois State Police cancelled a contract with Bode Technology Group, one of the largest independent DNA labs in the country, expressing outrage over poor quality work.
In North Carolina, the Winston-Salem Journal published a series of articles that documented numerous testing errors by the North Carolina State Bureau of Investigation.
What does this litany of error and incompetence mean? According to Thompson, we are not seeing a sudden deterioration in the quality of DNA testing, but the identification of problems that have long existed but were successfully hidden.
The findings set out above have significant implications for public officials. This record should alert law makers, enforcers of the law and defenders of the accused that in creating a large state bureaucracy for the administration of a forensic DNA database, we assume a duty to protect the privacy and due process rights of those whose DNA is held in the possession of the state.
Most immediately, the onus is on the legislature to ensure that forensic DNA evidence is used to protect public safety – and is not used to pursue the wrongful prosecution of the innocent. This would indeed constitute a betrayal of the promise of DNA science.
Mixing up and cross-contaminating DNA samples
Professor Thompson has documented error rates in DNA laboratories that are unexpectedly high. He has observed that the problem is widespread; that it occurs even in the best labs; and that forensic scientists have downplayed the scope of the problem and its import.
The sources of these errors are often shockingly mundane: labeling a sample with the wrong name; exposing DNA from one sample to DNA from another sample. But the consequences of such errors can be grave. Consider the example of the Washington State Patrol laboratory, which contaminated a DNA sample obtained from the scene of a rape with the DNA from a juvenile felon whose DNA reference sample was stored at the same lab. The lab had been using the juvenile's DNA sample in a training exercise when it was exposed to the sample from the rape case.
The juvenile offender, now an adult, was identified through a DNA match as the likely perpetrator of the rape. Fortunately, the crime in this instance was an old case. The alleged rapist would have been a child at the time the rape occurred. This factual anomaly led to the discovery of the circumstances that caused the cross-contamination of DNA samples by the lab. Absent the age discrepancy – and absent competent legal representation – an innocent man may well be serving time now for a crime he did not commit. And the sole cause of that wrongful conviction would have been the state's careless handling of a juvenile's DNA.
Judgment and misjudgment in DNA analysis
It is widely believe that DNA testing is an objective scientific procedure. But interpretation is involved in the analysis of a DNA specimen; and this interpretation can be highly subjective – and wrong.
The analysis of a DNA sample is conducted through the use of computer-generated graphs that display a series of peaks that correspond to alleles -- short, repeating segments of DNA. A computer analysis labels the alleles based on their length. Ambiguity can arise in interpreting the graphic representation of the DNA segments. The ambiguity is particularly great when a sample includes a mix of DNA from two or more individuals. Degradation of the sample can further mask multiple contributors to a DNA specimen. Spurious peaks in the graphs, which may be caused by air bubbles or other sources of distortion, can defy an analyst's effort to render a precise analysis.
Misinterpretation of test results led to the wrongful conviction of Timothy Durham in Tulsa, Oklahoma. Durham had been convicted of raping an eleven-year-old girl. He faced 3,000 year in prison, despite having produced eleven alibi witnesses who placed him in another state when the crime occurred. The conviction was based almost entirely on a DNA sample, which the prosecution said proved that Durham's genotype matched that of the semen donor. Post-conviction DNA testing demonstrated that the lab had misinterpreted a DNA sample with DNA strains from two individuals. The error was related to difficulty in separating the male and female DNA from the semen stain. It was the combination of alleles from two sources that produced a genotype that erroneously implicated Durham as a likely suspect. He was released in 1997, after serving four years in prison.
A study of forensic DNA evidence used in criminal prosecutions led Professor Thompson Professors Thompson and a team of his colleagues to publish the following warning about the nature of error in the analysis of forensic DNA:
|[L]aboratory data frequently reveal[ ] limitations or problems that would not be apparent from the laboratory report, such as inconsistencies between purportedly 'matching' profiles, evidence of additional unreported contributors to evidentiary samples, errors in statistical computations and unreported problems with experimental controls that raise doubts about the validity of the results.
Bias that favors the prosecution
There is little question, then, that human error may enter into the collection and handling of DNA samples, into the analysis of those samples; and into the reporting of what the analysis means. The potential for this type of error is exacerbated by the bias of crime lab analysts. Forensic scientists typically fail to take measures to "blind" themselves to the expected outcome of their analysis. Studies of this phenomenon indicate that when faced with ambiguity in the information presented in a DNA sample, crime lab analysts will often fit their interpretations to support the prosecution's theories.
According to Professor Thompson: "We often see indications, in the laboratory notes themselves, that the analysts are familiar with facts of their cases, including information that has nothing to do with genetic testing, and that they are acutely aware of which results will help or hurt the prosecution team. A DNA analyst in one case wrote: . . . 'Death penalty case. Need to eliminate [other individual] as a possible suspect."
The legislature must address the fact that to the extent error enters into the operation of the state's DNA database, the consequences of that error – including wrongful prosecution – will be borne overwhelmingly by persons of color. The criminal justice system is not race neutral. The gross racial disparities in the population incarcerated for drug offenses are but one example of this fact. The susceptibility of DNA evidence to error and abuse, as demonstrated by Professor William Thompson, should give immediate pause to legislators who are now asked to consider legislation that would greatly increase the number of DNA samples stored by the state.
As the state's DNA database expands, so too does the potential for error and abuse
When a system of DNA testing undergoes massive expansion, as has been proposed by Governor Spitzer, the potential for error that is inherent to the system will increase. Existing law and current practices demonstrate obvious flaws in the structure and operations of the state's DNA database. For example, New York law does not mandate external blind proficiency testing of DNA laboratories; such testing is discretionary and contingent. State law fails to recognize that in order to ensure the integrity of DNA laboratories, they must be independent of undue influence by law enforcement and other state agencies. The statute may inadvertently undermine that objective by directing that forensic labs cooperate and coordinate with criminal justice agencies. The state also permits localities throughout the state to collect and store the DNA of innocent persons, even when these individuals have been excluded as crime suspects. These so-called rogue databases operate outside the law, yet the state has taken no action to close the labs or to require compliance with regulatory procedures or guidelines. No legislation should be advanced regarding the DNA database until all laboratories are in compliance with state and federal laws.
Enhance regulation and oversight of the state's DNA database
The increasing use of human DNA as forensic evidence in criminal matters compels the state to undertake a system of rigorous protections that safeguard the rights and liberties of New Yorkers. Toward this objective, the NYCLU proposes that the legislature reconstitute the Commission on Forensic Science (whose current commissioners serve on a volunteer basis) and allocate to this new entity the human and financial resources required to provide comprehensive oversight of the state's DNA database.
This new commission would be afforded greater independence and autonomy than the existing commission. It would be mandated to establish and implement best-practice protocols as related to scientific methodology and laboratory procedures – including the authority to inspect and evaluate forensic DNA laboratories; develop audit procedures; review lab reports and test results, audit the outcome of criminal investigations involving DNA evidence, and provide direct supervision of management and supervisory practices in DNA laboratories.
I note, for the record, that this hearing was announced with very little notice. The issues before the committees are of significant importance and complexity; and yet they have been joined only in the final weeks of the legislative session. It was not possible, therefore, to address in depth the consequence for individual rights and liberties of the various proposals to expand or otherwise modify the state's DNA database. I would add, however, that as with the processing of DNA evidence, legislation that is hastily crafted and whose analysis is driven by heightened political dynamics is quite likely to produce a flawed result. I urge that the legislature give the issues before it today the full deliberation they require.