U.S. Supreme Court

Supreme Court Supports Prosecutors in DNA Lab Report Case; Expert Testimony Allowed

Prosecutors got a boost today in a 5-4 U.S. Supreme Court opinion upholding expert testimony in a case about a DNA lab report never admitted into evidence.

The opinion (PDF) in Williams v. Illinois was a loss for confrontation clause stalwart Justice Antonin Scalia, who joined a dissent by Justice Elena Kagan.

In 2009, Scalia wrote the majority opinion in Melendez-Diaz v. Massachusetts, which held crime lab evidence can’t be used at trial unless the analysts are subject to cross-examination. In Melendez-Diaz, the lab reports concerned the nature and quantity of a drug in a cocaine distribution case.

Williams v. Illinois, on the other hand, involved a DNA lab test never admitted in evidence that was discussed by an expert witness. Justice Samuel A. Alito Jr. wrote an opinion upholding the testimony that was joined by Justices Stephen G. Breyer, Anthony M. Kennedy and Chief Justice John G. Roberts Jr. Justice Clarence Thomas, who sided against prosecutors in the Melendez-Diaz case, supplied the fifth vote in a separate opinion that disagreed on Alito’s analysis.

University of California at Irvine law dean Erwin Chemerinsky has called the case “enormously important” though it has been little noticed. The practice used in the case—in which experts testify about DNA matches though they didn’t perform the test—is typical, he wrote for ABAJournal.com.

At issue in Williams was whether an expert witness could testify about an outside lab’s DNA profile created from semen taken from a rape victim. The DNA profile was entered into a database and a match was found. The man identified in the database was then put in a lineup and identified by the victim.

At trial, the expert read notations showing that the outside lab, Cellmark Diagnostics, had based its DNA report on vaginal swabs taken from the victim. She also said the Cellmark profile matched the suspect’s profile made by state police.

Alito said the testimony did not violate the confrontation clause. The remarks about the lab report were not admitted to prove the truth of the report, Alito said, and were not barred by the confrontation clause. “Under settled evidence law, an expert may express an opinion that is based on facts that the expert assumes, but does not know, to be true,” Alito said. “It is then up to the party who calls the expert to introduce other evidence establishing the facts assumed by the expert.”

Alito cited a second, independent basis for his finding that the confrontation clause is not violated. Even if the report had been admitted into evidence, he said, there would have been no confrontation clause violation. The report, he said, was produced before a suspect was identified. “The report was sought not for the purpose of obtaining evidence to be used against petitioner, who was not even under suspicion at the time, but for the purpose of finding a rapist who was on the loose,” he wrote. Besides, he said, the profile is not inherently inculpatory. “On the contrary,” he wrote, “a DNA profile is evidence that tends to exculpate all but one of the more than 7 billion people in the world today.”

Thomas said in his concurrence that he believes the expert’s testimony did turn on the truth of Cellmark’s statements, but the lab report is not a statement by a witness within the meaning of the confrontation clause. Thomas said the confrontation clauses reaches formalized testimonial materials, such as depositions, affidavits, and prior testimony, or statements resulting from formalized dialogue, such as custodial interrogation. The Cellmark report does not fall in those categories, he said.

Kagan’s dissent noted the five votes to approve admission of the expert testimony, but opined there was “not a single good explanation” among the plurality justices. “Under our confrontation clause precedents, this is an open-and-shut case” of a Sixth Amendment violation, Kagan wrote.

We welcome your comments, but please adhere to our comment policy and the ABA Code of Conduct.

Commenting is not available in this channel entry.