WASHINGTON The Supreme Court said Thursday that criminal defendants have a constitutional right to cross-examine the forensic analysts who prepare laboratory reports on illegal drugs and other evidence used at trial.
The court ruled 5-4 for a defendant who was convicted of cocaine trafficking, partly because of crime lab analysis.
Luis Melendez-Diaz challenged lab analysis that confirmed cocaine was in plastic bags found in the car he was riding in. Rather than accept the report, Melendez-Diaz said he should be allowed to question the lab analyst about testing methods, how the evidence was preserved and other issues.
Massachusetts courts rejected his arguments.
Justice Antonin Scalia, writing for the high court, said Melendez-Diaz has a constitutional right to confront the lab analyst.
Many states had argued that drug prosecutions would be slowed significantly if prosecutors had to make lab analysts available on a routine basis. Crime labs analyzed 1.9 million substances in following drug arrests in 2006, according to a court filing by 35 states.
About 20 states, including California, do give defendants some right to cross-examine lab employees about forensic evidence.
"Perhaps the best indication that the sky will not fall after today's decision is that it has not done so already," Scalia said. Many defense lawyers and their clients would just as soon not call added attention to evidence, he said.
But in dissent, Justice Anthony Kennedy said Scalia misunderstood how criminal trials work.
He predicted that criminal defense lawyers will accept the risk that the testimony will prove even more damaging to their clients on the chance the analyst isn't available to testify "and the government's case collapses."
The case produced unusual alliances. Scalia attracted the votes of Justices Ruth Bader Ginsburg, David Souter, John Paul Stevens and Clarence Thomas.
Joining Kennedy in dissent were Chief Justice John Roberts and Justices Samuel Alito and Stephen Breyer.
The case is Melendez-Diaz v. Massachusetts, 07-591.