Is Daubert or Frye used for expert witness testimony admissibility in Arizona?

The state of Arizona follows the Daubert test for the admissibility of expert witness testimony. Lear v. Fields, 245 P.3d 911 (Ariz. Ct. App. 2011). Under this test, expert testimony must be “(1) scientific knowledge that (2) will assist the trier of fact to understand or determine a fact in issue.” Id. To determine if these two factors are met, the court should analyze: “whether the theory or technique ‘can be (and has been) tested,’ ‘whether the theory or technique has been subjected to peer review and publication,’ ‘the known or potential rate of error,’ and whether the theory or technique has been generally accepted by the relevant scientific community.” Id. This test should be applied to both the conclusions the expert testifies to as well as the principles and methodology used by the expert. Id. Additionally, courts should apply the Daubert test to an expert’s own “skill and observation” in addition to the expert’s theory and technique. Id.