[JURIST] The US Supreme Court [official website; JURIST news archive] on Thursday ruled [opinion, PDF] 5-4 in Melendez-Diaz v. Massachusetts [Cornell LII backgrounder; JURIST report] that a forensic analyst's laboratory report is testimonial evidence under the Confrontation Clause [Cornell LII backgrounder] of the Sixth Amendment, giving criminal defendants a right to cross-examine the analysts. The Massachusetts Appeals Court held [opinion, PDF] that the report was not testimonial in nature and could therefore be admitted without the analysts testifying in person. Writing for the Court, Justice Antonin Scalia reversed that decision. Justice Clarence Thomas filed a concurring opinion. Justice Anthony Kennedy filed a dissenting opinion, joined by Chief Justice John Roberts and Justices Stephen Breyer and Samuel Alito.

In the 2004 case of Crawford v. Washington [opinion text] the Court held that testimonial evidence could not be admitted unless the defendant had an opportunity to cross-examine the witness. Since then, courts have struggled to determine what constitutes "testimonial evidence." At oral arguments, counsel for the state of Massachusetts had argued that such reports are not testimonial evidence, but rather are merely a "report of a scientist test."