A lab chemist must be called to testify in order to admit a lab analysis as evidence at trial, the Supreme Court recently held in Melendez-Diaz v. Massachusetts, 07-591 (June 22, 2009).  This case effectively ends the government’s routine practice of entering into evidence one sided, conclusory reports prepared by government lab technicians for the sole purpose of trial, which essentially allowed the prosecution to present its some of its strongest evidence without allowing a defendant to conduct any cross-examination.  In the case of Melendez-Diaz, the report in question contained no information about the qualifications or experience of the analyst who conducted the testing, the identity of the testing methods used to arrive at the analyst’s conclusions (and accompanying error rates), or whether any record-keeping or storage measures had been taken to preserve the integrity of the items for testing, among other things, which the defendant should have been able to cross examine the chemist who authored the report about.   To admit the report without the testimony of the chemist violated the defendant’s right of confrontation, affirmed by the Supreme Court’s decision in Crawford v. Washington, 541 U.S. 36 (2004).