The Constitution increasingly regulates the use of forensic evidence in criminal cases. This is a remarkable shift. In decades past, the U.S. Supreme Court declined to provide strong due process protection against destruction of forensic evidence or to obtain defense access to experts. In contrast, in recent years, the Court’s series of Confrontation Clause rulings tightened requirements to present live testimony in the courtroom. Perhaps far more significant, I will argue, the Court has strengthened obligations of defense counsel to litigate forensics, twice underscoring in little noticed opinions: “Criminal cases will arise where the only reasonable and available defense strategy requires consultation with experts or introduction of expert evidence.” In this Essay, I describe how despite decades of missed opportunities to adequately regulate forensics, in recent rulings the Court and to a far greater degree, lower state and federal courts, increasingly focus on sound litigation of forensics. In an era of plea bargaining, the accuracy of forensic analysis depends far less on cross-examination at trial, and far more on sound lab techniques, full disclosure of strengths and limitations of forensic evidence to prosecutors and the defense, and careful litigation. The changing judicial understanding of the constitutional significance of forensic evidence in criminal cases may follow from a new appreciation that forensic evidence is not only increasingly important in criminal cases, but that many traditional techniques lack adequate reliability and validity. The Sixth Amendment and the Due Process Clauses are emerging as promising constitutional sources for improved regulation of forensics, including through ineffective assistance of counsel and Brady v. Maryland rulings focusing on investigations and plea bargains. How meaningful courts will make those dual constitutional protections in the years to come will be a crucial test of our commitment to accuracy in criminal justice.
Brandon L. Garrett, The Constitutional Regulation of Forensic Evidence, 73 Washington and Lee Law Review 1147-1187 (2016)