WASHINGTON — 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 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.
In Orange County, the report prompted praise from William Thompson, an attorney and UC Irvine professor of social ecology who has written extensively about DNA testing, contending that current methods can result in too many improper results.
"DNA testing is important," Thompson said. "Everybody wants to see DNA testing developed and used. The real question is how to approach it with the care and caution that it warrants."
Dist. Atty. Michael R. Capizzi defended the DNA evidence used in a host of Orange County cases, saying it is reliable and has survived many court challenges to its admissibility.
"As with any scientific test, it requires the care and skill of the person performing it," Capizzi said. "We've had confidence in those we've called and utilized as experts."
The most prominent Orange County cases involving DNA typing included that of Kyle Joseph Borges, who was acquitted in April, 1989, of raping an Anaheim Hills woman because DNA tests showing he was the attacker were not ready in time for trial. Borges later pleaded guilty to raping a 12-year-old girl and a 50-year-old woman.
Orange County prosecutors used DNA evidence to win the July, 1991, conviction of Alfredo Martinez for a sexual attack on a newlywed Orange woman, and against Frank Lee Soto, who was convicted in March of attempted rape in an attack on a 79-year-old Westminster widow. DNA tests linked Soto to semen on the woman's bedspread.
At FBI headquarters, where most DNA testing is performed for states and localities, Director William S. Sessions said 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 that 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.