The Nation conducted a special investigation into the investigation and trial of Jimmy Genrich, a man whose “fate hung on the [analysis of] toolmarks, the only physical evidence that connected him to” a series of fatal bombings in Colorado. The investigation concludes that “Genrich’s case reveals a system that makes it nearly impossible to throw unproven forensic science out of courts and may be keeping thousands of innocent people behind bars.”

The piece details the progression of the investigation from the commencement of law enforcement interest in Genrich owing to his “history of mental illness” and attempt to purchase The Anarchist Cookbook during the time frame in which the bombings occurred. In an investigation of Genrich totalingmore than $1 million” the only potentially incriminating evidence located by the police included pliers and wire-strippers believed to be used in constructing the bombs. The police recruited forensic analyst John O’Neil to compare Genrich’s tools to marks found on recovered bomb fragments. O’Neil concluded, and later testified to the fact that “that Genrich’s tool must have cut the wire in the bomb, ‘to the exclusion of any other tool’ in the world.”

During Genrich’s trial, his legal team learned there were no scientific studies to back up toolmark comparisons. Furthermore “there was no standardized protocol to be followed. There were no criteria for how many points of similarity constituted a unique match. It seemed to be just O’Neil’s subjective judgment.” Despite these realities, the jury deliberated for four days and delivered a guilty verdict.

Today, Genrich is represented by the Innocence Project and is arguing that “the scientific consensus around toolmark evidence has changed.” He cites leading scientists at the NAS and PCAST who “say toolmark matching has not yet proved to be a scientifically reliable method,” and is “barely science at all.” Therefore, the kind of testimony O’Neil gave is “scientifically indefensible.” The Innocence Project argues this indefensible testimony constitutes “newly discovered evidence” and that Genrich deserves a new trial.

The piece concludes with a discussion of the future of toolmark comparisons. Toolmark analysis as a science is not without support, as a single study from 2009, that tested toolmark examiners’ abilities in a controlled setting, found that eight FBI toolmark examiners made no errors in analyzing marks left by screwdrivers. However, “one small study, in which the researchers have a vested interest in the outcome, on one type of tool is hardly a validation of the field.” As Judge Catherine Easterly wrote in a recent opinion in the DC Court of Appeals, until scientists conducting toolmark comparisons can establish regulations and a clear error rate, “a certainty statement regarding toolmark pattern matching has the same probative value as the vision of a psychic: it reflects nothing more than the individual’s foundationless faith in what he believes to be true.”