WASHINGTON — The Supreme Court on Tuesday questioned the testimony of a DNA expert that helped convict a man of rape, the latest high- court case to focus on the meaning of the constitutional requirement that defendants be able to confront witnesses against them.
The justices considered the convicted rapist’s claim that his constitutional rights were violated when the expert testified that the man’s DNA matched a sample taken from the victim, even though the expert played no role in the tests that extracted genetic evidence from the victim’s sample. In addition, no one from the company that performed the analysis showed up at the trial to defend it.
The court has previously ruled that defendants have the right to cross-examine the forensic analysts who prepare laboratory reports used at trial.
Match expert testified
In this case, Illinois says the forensic expert who matched the two samples played the critical role and that she testified and was subjected to a thorough cross-examination.
But Justice Antonin Scalia, who has led the court’s decisions in favor of defendants in these cases, said the state’s argument leaves important questions unanswered.
“We don’t know how good the individuals who did the test were. And that’s why it’s up to the state to bring forward testimony saying what the lab did. And the only testimony they brought forward was the testimony of this witness who was not there,” Scalia said.
The Obama administration, 42 states and several local prosecutors cautioned that if the court sides with the defendant, Sandy Williams, it could make it much harder for scientific experts to testify about their professional opinions, a common occurrence at criminal trials.
Missing “Hamlet”
A brief filed by the Manhattan district attorney and New York medical examiner warned that as many as 12 employees might have to testify to allow for the use of DNA profiles if the high court sides with Williams.
“The key actor in the play, the Hamlet in the play, is the person who did the test at Cellmark,” he said.
“And she or he is not here,” Justice Anthony Kennedy said, referring to the court’s decision in June, Bullcoming vs. New Mexico, which ruled that testimony from colleagues and supervisors uninvolved in the testing was not acceptable.
“In Bullcoming, at least you had an expert say how the laboratory works,” Kennedy said, in a tone approaching exasperation. “Here, you don’t even have that. You have less here with reference to Cellmark than you did in Bullcoming.”
Justice Stephen Breyer, who has sided with the government in the cross-examination cases, said he worries that a decision in favor of Williams would cause prosecutors to make less use of DNA evidence and “instead encourage them to rely on the less reliable evidence, namely the eyewitness testimony.”
