Science Panel Backs DNA Evidence in Criminal Cases

A scientific panel concluded Tuesday that “DNA fingerprinting”--a genetic identification technique often used to help apprehend and convict criminals--is reliable enough to be used as legal evidence in a criminal trial. But the panel called for higher standards for laboratories and personnel performing the procedure.

While generally endorsing the controversial technique, known also as “DNA typing,” the panel, sponsored by the National Academy of Sciences, said that reliability depends on a “high level of quality control in the process of collecting, analyzing and interpreting the data.”

Laboratories should be held to uniform national standards and technicians should be certified, the report by the 12-member committee concluded.

At FBI headquarters, where most DNA testing is performed for states and localities, Director William S. Sessions said that the panel’s findings are “consistent with principles which have guided the FBI’s DNA program from the beginning.”

John W. Hicks, director of the FBI laboratory, said during a news briefing that the lab’s standards for DNA testing are so uniformly high that he is convinced they could meet whatever criteria ultimately are developed by a science academy study group.

“We welcome the report and we’re looking at it favorably,” Hicks said. “If we find some reasonable basis for adjusting our approach, we will do it. We do not see it now.”

In DNA fingerprinting it is possible to match an individual with biological evidence--such as skin, blood, semen or hair--gathered at a crime scene. The technique is based on the fact that the genetic pattern carried in a molecule of deoxyribonucleic acid, or DNA, in every cell, is unique for each person, except identical twins.

The techniques used to distinguish one person’s DNA from all others are not yet as fully developed as other means, such as fingerprint analysis.

Therefore, the likelihood that a particular DNA sample belongs to a particular person is always stated in court as a probability and is usually considered by juries as one piece of evidence among many. Often, DNA typing is more effective in excluding a person as a suspect, Hicks said.

DNA has been used for identification purposes in U.S. court cases since 1986 but its validity has been questioned and challenged by defense lawyers in case after case involving murders, rapes and paternity suits.

Some courts have barred DNA evidence on grounds that the techniques used must first be generally accepted within the scientific community.

Paul Rothstein, a law professor at Georgetown University, said that the report “does a service in pointing to questions that need to be raised in court as to whether a DNA test was done the right way. A lot of defense lawyers have not been equipped to ask the right questions.”

According to the panel, testing laboratories have not always been required to meet “the highest standards of scientific rigor.”

Recommending uniform standards, it said that each DNA typing procedure “must be completely described in a detailed, written laboratory protocol” and should be documented by “a precise and objective . . . rule for declaring whether two samples match.” Panel members said that they found “a lack of standardization of practices and a lack of uniformly accepted methods for quality assurance,” attributing these deficiencies to “the rapid emergence” of this genetic technique in law enforcement.

Although the panel minimized speculation that many DNA-convicted defendants might have their cases reversed because of deficiencies, Rothstein said that it is “disingenuous to think that some percentage of cases won’t be re-examined.”

Rothstein is a member of the criminal evidence and procedures committee of the American Bar Assn. Hicks said that the FBI has used DNA typing in more than 5,000 cases, and “overwhelmingly, the courts have accepted the results.”

He added that “we’re confident the technology will not produce false results” but that “administrative errors always are possible.” Besides the FBI laboratory and about a dozen state police labs where technicians have received FBI training, there are a few private testing labs with no connection to the FBI, officials said.

Sessions and Hicks said that the FBI called its news briefing to counter an article on the panel’s findings in Tuesday’s New York Times that they called inaccurate. The panel’s chairman, Victor A. McKusick, professor of medical genetics at Johns Hopkins University, also told a separate news conference that the article was “misleading.”

McKusick said his panel concluded that, while improvements in techniques are needed, there is no reason to suspend the use of DNA evidence in the nation’s courts while deficiencies are being corrected.

“On the contrary,” he said. “We confirm the general reliability of using DNA typing in forensic science. When performed properly, the technique is capable of providing strong evidence for solving crimes.

“We think it is a powerful tool for criminal investigation and for exoneration of innocent individuals and one that should continue to be used even as standards are strengthened.”

Sessions said in a statement that the panel’s report “recognizes the utility of DNA evidence in criminal justice applications, encourages development of national standards for DNA testing laboratories and acknowledges the worth of a national DNA database to enhance law enforcement.”

The FBI is working with state and local crime labs to develop a national index system that “will store DNA profiles from serial rapes as well as the profiles from convicted sex offenders and violent criminals,” Sessions explained.

The study committee recommended that courts “accept the reliability of DNA typing and recognize that current laboratory techniques are fundamentally sound.”

However, in determining admissibility of specific evidence, courts should continue to consider “on a case-by-case basis the reliability of specific techniques” used to analyze samples, the report said.

The study also pointed to ethical and social concerns raised by the new technology since DNA is capable of revealing information about inherited diseases and other traits. Because data banks set up for law enforcement purposes also could be of interest to potential employers and insurance companies, the report said that laws should be enacted to control access to DNA information.