05/14/2026
Chancellor & Dean David Faigman, an expert on scientific evidence, told Law360 that there has been a dramatic shift in how courts view toolmark evidence. Faigman testified as an expert witness in post-conviction proceedings in the Colorado case of James Genrich, who was convicted in 1991 of setting pipe bombs around Grand Junction, Colo., killing one person and injuring several others.
Faigman testified that a toolmark identification expert who told the jury that a wire in an unexploded bomb matched a defendant’s pliers “to the exclusion of any other tool in the world” had improperly overstated the reliability of the evidence. Ultimately, prosecutors in Mesa County, Colo., dropped their effort to retry Genrich. "In a relatively short period of time over the last six, seven years, there has been a sea change in how courts see fi****ms and toolmarks," Faigman told Law360. "There are just a lot of areas of forensic science that we have now moved away from because we know that they were not valid, and they should never have come into court in the first place, and that's essentially true for fi****ms and toolmarks."
A handyman was convicted for a string of 1991 Colorado bombings based on a forensic expert's testimony that the handyman's tools matched markings on bomb fragments "to the exclusion of any other tool in the world." Decades later, the defendant's successful challenge to the scientific merit and relia...