The United Supreme Court ruled today that the Sixth Amendment's Confrontation Clause gives criminal defendants the right to cross examine the scientists who issue forensics reports that are entered into evidence. The breakdown of the 5-4 ruling in Melendez-Diaz v. Massachusetts (07-591) was interesting, with Justice Scalia's majority opinion joined by Justices Thomas, Ginsberg, Souter and Stevens. Alito, Roberts, Kennedy, and Breyer dissented.
The ruling will provide for an added layer of challenge by defense lawyers to such criminal evidence as illegal drugs, fingerprints, blood spatter patterns and blood chemistry, guns and bullets, and other forms of physical evidence subjected to lab analyses, at least when the resulting reports are prepared for use as evidence in criminal trials.
Now, if prosecutors want to offer a crime lab report as evidence, and the report was prepared with the aim that it would be used at trial, the prosecution has to bring along the author or scientist and make them available for questioining by the defense — if the defense insists on the right to confront the analyst. It is not up to defense lawyers to summon them to the stand, but they must assert the right to confront the analyst, the Court indicated. A copy of the opinion can be found at http://www.supremecourtus.gov/opinions/08pdf/07-591.pdf.