State of Arizona, Petitioner v. the Honorable Jerry Bernstein, Judge Pro Tempore of the Superior Court of the State…

Summary

The court held that Rule 702(d) requires trial courts to examine whether an expert reliably applied a generally reliable methodology, but errors in application warrant exclusion only when they make the results themselves unreliable. The trial court therefore abused its discretion by excluding BAC evidence based on general instrument concerns, data drops, mislabeling incidents, and unresolved malfunctions without evidence that the defendants’ particular results were inaccurate or unreliable. The court vacated the exclusion order and remanded for further proceedings.