State Justices Uphold DNA Evidence, With Limits

In its first ruling on DNA test results, the California Supreme Court upheld the admissibility of such evidence Monday but said prosecutors will have to show that correct scientific procedures were followed on a case-by-case basis.

Although DNA evidence has been used in many California cases, prosecutors had to go through extensive hearings to prove that DNA testing was generally accepted scientific technology, and some state appellate courts had expressed reservations about it.

The Supreme Court’s unanimous ruling settled conflicting holdings by lower courts. Although the decision cleared the path for admitting certain kinds of DNA evidence, the ruling also sent a strong message that the high court will not tolerate sloppy or inaccurate applications of these methods.

“What this opinion says is there are still a lot of unresolved questions about DNA, and those questions will be rigorously examined by appellate courts,” said University of Santa Clara law professor Gerald Uelmen, a court analyst.

The court approved the use of a DNA test known as RFLP, which can with a high degree of certainty show a match based on only a speck of blood or other specimen.

But the decision disappointed some prosecutors because it did not endorse a method that purports to identify suspects with near-fingerprint accuracy. This method can provide dramatic evidence showing the likelihood of an accidental match is one in several billion. Prosecutors relied partially on such calculations during the O.J. Simpson murder trial.

Instead, the ruling written by Justice Marvin Baxter embraced a more conservative approach that puts the likelihood of a false match as one in hundreds, thousands or at the most, millions.

The more definitive figures still can be used if the Supreme Court decides they are acceptable in a case still pending before the court or if prosecutors can convince trial judges that the calculations already have scientific approval.

The law-and-order Criminal Justice Legal Foundation praised the decision for clearing the way for DNA evidence in trials throughout California. “The decision prevents future court challenges on this type of evidence,” the group said.

Uelmen, a defense lawyer for Simpson, called the decision “great news” that will be “extremely helpful to the defense” in criminal cases.

The rigor of the analysis in the ruling, Uelmen said, shows that the Supreme Court “is not going to gloss over” and rubber-stamp all DNA evidence.

The court’s ruling, though upholding the use of DNA evidence, actually overturned the rape conviction of Sergio Venegas. He was tied to a 1989 sexual attack in a Bakersfield motel largely by DNA analysis of his semen.

In Venegas’ trial, an FBI criminologist testified that the genetic profile of evidence found at the crime scene was shared by only one in 65,000 people or one in 31,000 among southwestern Latinos.

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The Supreme Court upheld the basic RFLP methodology that the FBI used to match semen at the crime scene to Venegas. But the court said Venegas is entitled to a new trial because the FBI failed to follow correct scientific procedures in calculating the statistical probability of a random match.

Baxter noted that the prosecution has admitted that without the DNA evidence, “there was insufficient evidence to convict” Venegas. “It was reasonably probable defendant would have had a more favorable verdict had the trial court not erroneously admitted DNA evidence,” Baxter wrote.

Deputy Atty. Gen. Jo Graves expressed confidence that Venegas, who was serving a 65-year prison sentence, would be found guilty in a retrial because the statistical methods approved by the court would still prove he is the rapist.

“Right now this limits us to the more conservative calculations,” Graves noted.

Specifically, the Supreme Court held that a 1992 National Research Council procedure for calculating the likelihood of a random match is generally accepted by scientists, and hearings on its admissibility are not necessary. The court said the council’s early recommendations erred on the side of caution.

“Virtually all of the scientists who have criticized [the 1992 recommendations] do so on the basis that those statistical methodologies produce figures that are far too conservative and unduly favorable to the suspect,” Baxter wrote.

But trial courts must still determine whether the calculations “in the particular case followed correct scientific procedures,” Baxter wrote.

Deputy State Public Defender Valerie Hriciga said the ruling “really reaffirmed the trial court’s power to act as a gatekeeper and keep out the result of genetic tests when generally accepted scientific procedures were not followed.”