Expressing a heavy dose of skepticism that crime lab reports are so reliable as to be beyond question, the Supreme Court on Thursday cleared the way for chemists and other scientists who prepare such reports to be summoned to the witness stand in criminal trials to defend their analyses. The 5-4 ruling in Melendez-Diaz v. Massachusetts (07-591) resulted from some unusual alliances among the Justices, and continued the deep division within the Court over how to interpret the Constitution’s guarantee that an individual on trial for a crime has a right to face and challenge the witnesses for the prosecution.Justice...