Arizona is a Frye state. The Arizona Supreme Court rejected Daubert in Logerquist v. McVey, 196 Ariz. 470, 1 P.3d 113 (2000). The Arizona Rules of Evidence are available online from West (free registration required). Selected decisions are digested below.
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Arizona Supreme Court
State v. Davolt, 84 P.3d 456 (Ariz. 2004). Days before trial, capital defendant moves to exclude DNA evidence, arguing that random match statistics are not generally accepted under Frye. Trial court denies motion and jury convicts. Admissibility affirmed. DNA evidence based on product rule method of calculating probability of match is acceptable when database satisfies Frye requirements. See State v. Hummert, 188 Ariz. 119, 123, 933 P.2d 1187, 1191 (1997). Defendant's motion was not supported by credible authority that product rule evidence is generally unacceptable, and was therefore properly denied on merits. Motion was also untimely because filed fewer than twenty days before trial. Defendant also complains that several prosecution forensic witnesses were unqualified, but all of them possessed sufficient qualifications.
State v. Lehr, 201 Ariz. 509, 38 P.2d 1172 (2002), cert. denied, 537 U.S. 1020 (2000). Based on incidents involving attacks on ten separate women, defendant is charged with multiple counts of murder, attempted murder, aggravated assault, kidnapping, sexual assault, attempted sexual assault, sexual conduct with minor, and sexual conduct with child under age of fourteen years. When defendant objects to prosecution's DNA evidence, trial court takes notice that theories underlying DNA analysis are generally accepted in scientific community, and rules after Frye hearing that protocols followed by prosecution's labs are generally accepted as well. At trial, defendant attempts to cross-examine prosecution experts re protocols, but prosecution objects that defendant may not relitigate matters already decided by trial judge. Trial court sustains objection. Invoking Ariz. R. Evid. 403, trial court also bars defendant from presenting his own expert testimony on protocols. Jury convicts. Exclusion reversed. Trial court's decision on admissibility of evidence should not have barred defendant from contesting its weight before jury. Prohibition of cross-examination on that subject violated defendant's Sixth Amendment right of confrontation. Exclusion of defendant's own expert testimony on same subject violated his Sixth Amendment right to present testimony. Error was not harmless as to counts where prosecution's case relied heavily on DNA evidence.
Logerquist v. McVey, 196 Ariz. 470, 1 P.3d 113 (2000). In 1991, television commercial triggers adult woman's memory of sexual abuse by her pediatrician between 1971 and 1973, when she was 8 to 10 years old. In suit against pediatrician, woman relies on clinical psychiatrist Dr. Bessell van der Kolk, who testifies at Frye hearing that severe childhood trauma can lead to dissociative amnesia and post-traumatic stress disorder, causing repression of traumatic memories that may not be recalled until years later. Defendant's expert, research psychologist Dr. Richard Kihlstrom, testifies at same Frye hearing that research supporting repressed memory is plagued by flaws, and that other studies have found that trauma usually enhances memory. Trial judge concludes that plaintiffs' theories do not enjoy general acceptance and excludes testimony from plaintiff's expert. Court of appeals denies plaintiff's petition for interlocutory review, but Arizona Supreme Court grants it. Exclusion reversed. Plaintiff contends that Frye is inapplicable, and that if Frye were applicable, Arizona courts should discard it in favor of Daubert. Defendant contends that Frye applies and bars plaintiff's expert testimony, and that Daubert would bar it as well. For multiple reasons [lengthy discussion], Arizona will reject Daubert and continue to apply its precedents and Ariz. R. Evid. 702 "as written." Under those authorities, "Frye is applicable when an expert witness reaches a conclusion by deduction from the application of novel scientific principles, formulae, or procedures developed by others." But that description does not apply to this case, and "Frye is inapplicable when a qualified witness offers relevant testimony or conclusions based on experience and observation about human behavior for the purpose of explaining that behavior." Trial court therefore erred in applying Frye and in screening plaintiff's expert testimony for general acceptance.