Author: Molly Doolittle

In this case, a toolmark “expert” testified against James Genrich by assuring the jury that several of Genrich’s tools made purportedly unique marks on fragments of the bombs recovered from the crime scene, “to the exclusion of any other tool” in the world. That testimony all but assured Genrich’s conviction. But as this brief describes, the scientific community has now recognized that it is not appropriate to express such a conclusion in the area of toolmarks, or in any forensic discipline. “The reality is that uniqueness is impossible to prove, and is not anywhere near as relevant as some may claim[.]”2 Part I.A of this brief describes how the relevant field of toolmark comparisons lacks scientific research support. While firearms comparisons, which are far more commonly conducted, have been the subject of some studies, toolmarks research is nearly nonexistent. Part I.B describes the “theory” used to advance toolmark identifications in court and explains why scientists have found it unsupported. The section also describes criticism of toolmark comparisons in influential scientific reports that have highlighted problems of overstated testimony, error rates, and lack of research. Part I.C describes toolmark identifications in the courts and how, in recent years, courts have excluded or limited testimony like that presented in the Genrich case. Finally, Part II describes how the flaws inherent in toolmark evidence were borne out in this particular case. In light of the unreliable nature of toolmark evidence, Amici respectfully urge this Court to grant a full evidentiary hearing to review the faulty and wholly unscientific forensic testimony that led to Genrich’s conviction.

In this Essay, I describe how despite decades of missed opportunities to adequately regulate forensics, in recent rulings the Supreme Court and lower 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 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, as well as the general due process guarantee of a fair trial.