¶74 (dissenting) — Because I believe the trial court erred in excluding Dr. Roberto Ramos’s testimony that methamphetamine can cause a person to act aggressively and irrationally, I dissent.
*398¶75 The trial court characterized Dr. Ramos’s testimony as irrelevant and speculative because Dr. Ramos could not say what specific behavior the victim’s high level of methamphetamine would have caused. But the defendant was not obligated to prove to a certainty, or even beyond a reasonable doubt, how methamphetamine would have affected the victim’s behavior. Rather, evidence of the high levels of methamphetamine in Holdorph’s system was relevant because Lewis asserted self-defense and claimed that Holdorph was the aggressor. Specifically, Lewis testified that Holdorph, although not armed, charged and attacked him. Dr. Ramos’s testimony that methamphetamine can cause such irrational aggressive behavior supported Lewis’s story, making it more credible.
¶76 Moreover, unlike alcohol, the average juror is not likely to understand methamphetamine’s physiological effects on the human body. Cf. State v. Thomas, 123 Wn. App. 771, 782, 98 P.3d 1258 (2004) (jurors can draw reasonable inferences from testimony about alcohol use) (citing State v. Kruger, 116 Wn. App. 685, 692-93, 67 P.3d 1147 (2003))), review denied, 154 Wn.2d 1026 (2005). That Dr. Ramos could not testify regarding the specific effects that methamphetamine had on Holdorph goes to the weight of his testimony, not its admissibility.
¶77 In State v. Rangitsch, 40 Wn. App. 771, 779, 700 P.2d 382 (1985), the court held that the trial court did not abuse its discretion in admitting expert testimony regarding the effects of cocaine use on human behavior and perception. In Rangitsch, the evidence established that the defendant was under the influence of cocaine when he caused a fatal car collision. Rangitsch, 40 Wn. App. at 773-74. To establish a nexus between the defendant’s drug use and the auto accident, the State offered expert testimony regarding cocaine’s effects on a person’s motor skills and ability to drive. Rangitsch, 40 Wn. App. at 775. The court held that the trial court did not err in allowing the expert testimony under ER 702. Rangitsch, 40 Wn. App. at 779.
*399¶78 Perhaps more instructive is the Arizona Supreme Court’s decision in State v. Plew, 155 Ariz. 44, 745 P.2d 102 (1987). In Plew, the court held that “the effect of cocaine intoxication on mental and physical behavior is a proper subject for expert testimony in an appropriate case.” Plew, 745 P.2d at 106. There, the defendant in an attempted murder case tried to show that he shot the victim, who was high on cocaine, in self-defense after the victim pointed a gun at him. Plew, 745 P.2d at 103. The defendant sought to introduce expert testimony regarding the general effects of “cocaine intoxication,” but the trial court ruled the evidence inadmissible due to a lack of proof that the victim was under the influence of cocaine and a lack of particularized information about the drug’s effect on the victim. Plew, 745 P.2d at 104. The Arizona Supreme Court held that because the testimony would have assisted the jury in understanding the evidence, the court should have admitted the expert testimony under Rule 702, Arizona Rules of Evidence. Plew, 745 P.2d at 106. The court stated that the expert’s testimony was particularly appropriate because the defendant claimed self-defense, alleging that he tried to protect himself from the attack of a person under the influence of cocaine—a condition that is not within the experience of the average juror. Plew, 745 P.2d at 106.
¶79 Here, the trial court allowed evidence that the victim had a relatively high level of methamphetamine in his blood. But the court rejected Lewis’s attempt to explain the possible effects of methamphetamine, several of which supported his self-defense claim. In so ruling, the court denied Lewis his constitutional right to present a defense. See State v. Cheatam, 150 Wn.2d 626, 648, 81 P.3d 830 (2003) (citing Washington v. Texas, 388 U.S. 14, 19, 87 S. Ct. 1920, 18 L. Ed. 2d 1019 (1967)). I would reverse and remand for a new trial.
Review denied at 163 Wn.2d 1030 (2008).