State of Arizona, Appellee v. Joseph Javier Romero, Appellant

Summary

The court held that the trial court improperly excluded defense expert testimony criticizing the scientific rigor of firearms toolmark analysis. The defense expert was qualified in experimental design, and his testimony would have helped the jury evaluate the weight and credibility of the State’s firearms evidence. The court vacated the relevant portion of the appellate decision and remanded for a harmless-error determination.