Smith, J.
Petitioner Joey C. Ellis seeks discretionary review of an order of the Pierce County Superior Court dated July 29, 1997 granting Respondent State of Washington’s motion in limine to exclude expert testimony on [500] diminished capacity and denying Petitioner’s motion to allow the testimony in a pending trial in which Petitioner is charged with two counts of aggravated murder in the first degree and in which the State seeks the death penalty. We granted review on September 4, 1997 staying Petitioner’s trial which had been scheduled for September 15, 1997. We reverse the Superior Court.
QUESTION PRESENTED
The question presented in this case is whether the trial court erred in excluding proffered defense expert testimony on diminished capacity, thus denying Petitioner an opportunity to establish a diminished capacity defense.
STATEMENT OF FACTS
On February 16, 1996, the Pierce County Prosecuting Attorney filed a corrected information in the Pierce County Superior Court charging Petitioner Joey C. Ellis with two counts of aggravated first degree murder1 for the deaths of his mother, Lindy Lou Ellis, and his two-year-old half-sister, Jaime Jane Ellis.2 The information states that on or about January 8, 1996 Petitioner, with premeditated intent,3 bludgeoned his mother and half-sister to death with a [501] breadboard.4 The information claimed as an aggravating circumstance that “the murders were part of a common scheme or plan, or the result of a single act of the defendant, or . . . was [sic] committed in the course of, in furtherance of, or in immediate flight from Robbery in the First or Second Degree . . . .”5
On September 19, 1996, the State filed a discovery motion for disclosure of any mental defense Petitioner intended to present at trial. The State acknowledged receipt from Petitioner, as part of a mitigation package, of a report by Dr. Lloyd I. Cripe, Ph.D., a clinical neuropsychologist. The State observed that “Dr. Cripe discusses in detail his analysis of the [Petitioner’s] state of mind when he killed the victims. However, Dr. Cripe does not address, one way or the other, the question of diminished capacity. Based upon past experience and the nature of this case—legally and factually—the [State] anticipates that diminished capacity (or even insanity) will be raised at trial.”6
On September 23, 1996, the State filed a notice of intent to seek the death penalty, stating that “either no mitigating circumstances have been brought to the attention of this office, or such mitigating circumstances as have been submitted have been received and considered and are not sufficient to merit leniency.”7 By letter dated January 3, 1997, Petitioner’s assigned counsel informed the State of his diminished capacity defense, naming three psychologists as expert witnesses, “Mark Whitehill, Ph.D., Lloyd [502] Cripe, Ph.D., and Jon Conte, Ph.D.”8
In his mitigation report dated August 7, 1996, Dr. Cripe stated that he reviewed police reports and records, interviewed a close family friend, interviewed Petitioner’s probation officer, and conducted a neuropsychological evaluation of Petitioner. He determined that Petitioner “suffered extreme psychological pain and a damaged self-esteem” as a result of growing up in a very dysfunctional and abusive environment.9
In an addendum to his report dated January 2, 1997, Dr. Cripe determined that Petitioner suffered from a “mental illness related to a long history of child and adolescent abuse which combined with drug abuse and the circumstances the night of the homicides resulted in a diminished capacity to normally control his mind and behavior.” Dr. Cripe recommended that Petitioner “be defended with an understanding [sic] a diminished capacity at the time of his extreme actions.”10
In a summary of findings dated January 3, 1997, Dr. Mark B. Whitehill, Ph.D., clinical and forensic psychologist, stated that he reviewed taped statements Petitioner made to the police following his arrest, examined the results of Petitioner’s polygraph examination, interviewed a longtime family friend, and conducted a battery of psychological tests of Petitioner. He concluded that Petitioner satisfied the “statutory criteria ... in State v. Edmon (28 Wn. App. 98, 621 P.2d 1310) for diminished capacity defense”.11
On June 4, 1997, the State filed a motion in limine to exclude or limit expert testimony.12 On June 7, 1997 Petitioner filed a motion to admit expert testimony on diminished capacity.13 Both parties cited a 1981 Court of [503] Appeals decision, State v. Edmon,14 which stated nine foundational requirements for admitting expert testimony-on diminished capacity. At a hearing before the Honorable Vicki L. Hogan on June 16, 1997, defense counsel elected not to call witnesses, but relied upon their written motions. The State called as “hostile witnesses” defense experts Dr. Conte, Dr. Cripe and Dr. Whitehill and appropriately asked leading questions. Over defense objections, the court allowed testimony by Dr. Greg J. Gagliardi, Ph.D., of Western State Hospital, who gave his opinion concerning the appropriate methodology for diagnosing diminished capacity and application of “Edmon factors” in psychological diagnosis.15 In an oral ruling on June 17, 1997, Judge Hogan granted the State’s motion in limine to exclude the testimony of defense expert witnesses Dr. Conte, Dr. Cripe and Dr. Whitehill.16 Petitioner moved for reconsideration, requesting the court to allow an offer of proof through further testimony and declarations.17 The court granted the motion. After hearing the testimony of Dr. Cripe on July 28, 1997, Judge Hogan affirmed her prior ruling.18 The court did not allow further testimony from Dr. Whitehill, determining there was “nothing new in Dr. Whitehill’s July 23rd declaration that indicates anything new than as testified.”19
On July 29, 1997,20 Judge Hogan signed an order granting the State’s motion in limine to exclude or limit expert testimony and denying Petitioner’s motion to admit expert evidence on diminished capacity.21 On August 8, 1997 [504] Petitioner sought discretionary review by this Court.22 Review was granted on September 4, 1997.23
DISCUSSION
The usual rule is that admissibility of evidence is within the sound discretion of the trial court and the court’s decision24 will not be reversed absent abuse of that discretion.25 “An abuse of discretion occurs only when no reasonable person would take the view adopted by the trial court.”26
Petitioner asserts that diminished capacity is a mental condition, not amounting to insanity, that causes an inability to form the requisite intent for the crime charged.27 Citing State v. Eakins, Petitioner acknowledges that for a defendant to maintain a diminished capacity defense, the defendant must present expert testimony establishing a mental disorder that impaired the ability to form the specific intent28 to commit the offense charged.29 Petitioner argues that determination of the credibility of expert witnesses is for the jury.30
Asserting that State v. Edmon establishes the foundational criteria for admitting the opinion of an expert regard[505] ing a defendant’s ability to form a specific intent, Petitioner argues that he has satisfied all nine “Edmon factors”31 and therefore the trial court erred in excluding his expert testimony.
Petitioner argues that “Edmon factor” one has been satisfied because, in the expert opinion of Dr. Cripe, Petitioner could not have formed a specific intent at the time of the killings.32 Petitioner contends that “Edmon factor” two has been satisfied because the experts’ qualifications were not challenged and the court, either expressly or implicitly, acknowledged that the experts were qualified to testify.33 Petitioner argues that “Edmon factor” three has been satisfied through the testimony of Dr. Whitehill on June 16, 1997 and Dr. Cripe on July 28, 1997, when they stated that they examined and diagnosed Petitioner and were able to state an opinion with reasonable medical certainty.34
[506] According to Petitioner, the expert testimony is based upon substantial supporting evidence in the record and therefore “Edmon factor” four has been satisfied. Dr. Whitehill testified he relied on his discussions with Petitioner and additional information, including a previous mental health examination.35 Dr. Cripe testified he relied upon examination of Petitioner and “records surrounding the case and the police and legal aspects of the case.” He stated he received “some input from Dr. Whitehill,” and interviewed a woman with whom Petitioner and his mother had lived and interviewed Petitioner’s grandfather.36
Petitioner contends he has satisfied “Edmon factor” five because expert testimony concluded his mental disorder, and not ordinary emotions, prevented him from forming a specific intent. Dr. Whitehill testified he would characterize Petitioner’s personality disorder on multiple levels, a behavioral component, a cognitive component, an interpersonal relations component, and an emotional component.37
During his testimony, Dr. Cripe explained that Petitioner was not experiencing mere transient emotion, but the emotion was a component of an underlying mental disorder.38
Arguing that “Edmon factor” six has been satisfied, Petitioner contends defense experts explained that his mental disorders caused his inability to form intent. Dr. Whitehill testified that Petitioner experienced an aberrant reaction, “We are talking about extreme pathology here, and breakdowns of mental observations that are not just an overreaction. We are talking about defects of mental functioning.”39 Dr. Cripe explained that, due to the unusual and extraordinary nature of the crime, he believes Petitioner was not merely experiencing reduced perception or other irrelevant mental states.40
[507] Petitioner asserts that “Edmon factor” seven has been satisfied because in Dr. Whitehill’s expert opinion, Petitioner’s inability to form a specific intent occurred at the time of the killings.41 Petitioner also refers to Dr. Cripe’s statement that “when the situation evolved that night and interacted with [Petitioner’s] mental defect and impairment, there was just a breakdown in the way the mind works and the way the mind would normally prethink or deliberately reason things out and think about cause and effect and then make a decision.”42
Petitioner argues that the testimony of Dr. Whitehill and of Dr. Cripe satisfies “Edmon factor” eight, which requires that the mental disorder must substantially reduce the probability that Petitioner formed the necessary intent. Dr. Whitehill described Petitioner’s ability to form specific intent as “severely compromised” and estimated that Petitioner’s capacity to form intent was roughly at 25%, or reduced by 75%.43 Dr. Cripe testified that Petitioner’s mental disorders substantially reduced the probability that Petitioner formed the necessary intent.44
Petitioner contends “Edmon factor” nine has been satisfied because defense experts explained how his mental disorders caused an inability to form specific intent. Dr. Whitehill testified that, in his professional opinion as a forensic psychologist, Petitioner suffered diminished capacity on the night of the killings.45 In a declaration dated July 28, 1997, Dr. Cripe concluded that what happened on the night of the killings was not premeditated or intended.46
Petitioner concludes that because all nine foundational requirements of Edmon have been satisfied, the trial court erred in excluding the expert testimony of Dr. Whitehill and Dr. Cripe. According to Petitioner, this case and State [508] v. Edmon are “virtually indistinguishable.” Petitioner argues that in Edmon, the Court of Appeals reversed the defendant’s conviction because the trial court excluded expert testimony similar to testimony excluded in this case.
In Edmon, the defendant, who filed a grievance against his supervisor, believed he was a victim of racial discrimination. One night he arrived at work after drinking and partying and entered into an angry discussion with his supervisor. The defendant threatened, hit, and shot his supervisor in the stomach. One hour later, the defendant had a blood alcohol reading of .13. At trial, the defendant testified he had only 3 hours of sleep during the 24 hours preceding the shooting and that he could not recall the incident.47 The trial court excluded psychiatric testimony offered to show the defendant did not have the ability to form certain mental states as a result of the medically recognized mental disorders of anxiety and depression. The trial court also excluded expert testimony offered to prove greater impairment caused by the combined effect of alcohol, lack of sleep, and mental disorders.48 In an offer of proof, a psychiatrist testified that given the defendant’s background, his mental disorders, the difficulties with his supervisor, and the other circumstances surrounding the shooting, the defendant was “likely to be severely impaired in his ability to form the intent to kill or to injure.” The psychiatrist described the defendant’s circumstances as an “explosive scenario” and also testified that the alcohol and lack of sleep would tend to further dilute ego control.49
Petitioner Ellis argues that in his case, defense experts similarly explained that, as a result of his mental disorders, he suffered from a “significant loss of (already severely attenuated) ego-control”50 at the time of the killings. Petitioner challenges the State’s argument that the expert [509] testimony proves only an “irresistible impulse,”51 a defense not accepted in this State. Petitioner asserts that in Edmon, the court determined that ego-control, an entirely different matter from irresistible impulse, refers to the perceptive powers, and not to the volitive powers. Petitioner contends that under Edmon, mere reference to an “explosive scenario” does not convert expert testimony into testimony on irresistible impulse.52 The Court of Appeals stated in that case that “substantial reduction” of the probability that the defendant formed the challenged mental state is the required showing, not absolute certainty and “the jury then gives the opinion whatever weight it deserves.”53
Petitioner claims this case is an even stronger one to support diminished capacity than Edmon54 because he presented two experts who testified he suffered from two longstanding mental disorders, the State’s expert agreed he suffered from a personality disorder,55 he has been precluded from presenting a diminished capacity defense, and murder in the first degree requires premeditation, which necessitates a greater mental capacity than intent.
Relying on State v. Eakins,56 Petitioner claims the facts in this case are more compelling than in other cases in [510] which this Court allowed expert testimony on diminished capacity. In Eakins, the defendant was convicted of two counts of second degree assault while armed with a deadly weapon. This Court affirmed reversal by the Court of Appeals. The defendant went to a restaurant where his estranged girl friend worked and pointed a loaded revolver at her and the kitchen manager. Admitting he had pointed the gun, defendant claimed diminished capacity induced by drugs and alcohol. His therapist testified the defendant was depressed and suffered from a personality disorder for which he was taking prescription tranquilizers with alcohol. The therapist said he believed the defendant had consumed as much as 24 ounces of alcohol on the night of the assaults. A psychiatrist testified the defendant was incapable of forming the intent to assault because of his depression and the consumption of alcohol with his medication. He described the defendant’s behavior during the assaults as a “delirium induced by drugs and alcohol.” The two victims and two other witnesses testified the defendant appeared angry but not intoxicated or delirious the night of the assaults. Two police officers who interviewed the defendant four hours after the assaults testified he did not appear intoxicated and spoke clearly and coherently.
Petitioner argues the cases of Edmon and Eakins lead to the conclusion that the trial court erred in excluding his expert testimony on diminished capacity.
The State to the contrary asserts the trial court properly exercised its discretion to exclude expert testimony on diminished capacity because Petitioner has not satisfied the nine foundational requirements of Edmon. The State contends that Washington courts have consistently applied the “Edmon factors” in determining admissibility of expert testimony on diminished capacity.
Citing State v. Griffin, the State argues that a diminished capacity defense requires substantial evidence of a mental condition and requires that the evidence “logically and reasonably connects the defendant’s alleged mental condition [511] with the inability to possess the required level of culpability to commit the crime charged.”57
In Griffin, the defendant was convicted by a jury on three counts of forgery. Upon returning from service in Vietnam, he had been hospitalized for psychiatric treatment five times. A clinical psychologist and a psychoanalyst testified the defendant suffered from a catatonic paranoid schizophrenia and chronic alcoholism and therefore would be incapable of forming an intent to injure or defraud. The trial court refused an instruction on diminished capacity. The Court reversed the conviction, concluding that “[s]uch expert opinion on diminished capacity is admissible when relevant to the issue of defendant’s mental intent.” The Court determined there was “abundant evidence in the record to show defendant’s mental disorders impeded his ability to formulate the requisite intent” and denial of an instruction on diminished capacity was reversible error.
The State asserts that in State v. Davis58 the court applied the “Edmon factors” in excluding expert testimony on diminished capacity. In that case, the defendant was convicted of second degree felony murder and second degree assault. Citing Edmon, the Court of Appeals upheld the trial court’s decision to exclude expert testimony.
The State asserts that in State v. Thamert59 the court applied the “Edmon factors” in affirming the trial court’s decision to exclude expert testimony on diminished capacity. In that case, the defendant, who was convicted of two counts of second degree robbery, confessed to the crimes, explaining that “voices told him to rob the banks.” A psychiatrist testified the defendant suffered from chronic paranoid schizophrenia, an incurable disorder characterized by identity confusion, hearing voices, indecisive thinking, and poor impulse control and was therefore unable to [512] form the intent to steal at the time of the robbery. The court excluded the testimony of another psychiatrist, determining the offer of proof regarding that expert did not comply with three of the nine “Edmon factors” and that the testimony would be cumulative.
The State argues this case is distinguishable from Edmon, contending that defendant Edmon was diagnosed with the medically well-established mental disorders of anxiety and depression. The State claims that, in contrast, Petitioner Ellis has been diagnosed only with nonspecific mental disorders60 and the experts’ diagnoses were inconsistent.
The State refers to the testimony of Dr. Whitehill on June 16, 1997, in which he stated61 that Petitioner suffered from borderline personality disorder,62 although he was not [513] in a dissociative63 state at the time of the killings. At a later point in his testimony, he described Petitioner’s mental disorders as borderline personality not otherwise specified64 and intermittent explosive disorder65 or the parallel condition of impulse control disorder.66 In his summary of findings dated January 3, 1997, Dr. Whitehill concluded that Petitioner suffered from a severe personality disorder67 and impulse control disorder or intermittent explosive disorder.68
In testimony on June 16, 1997, Dr. Cripe stated that Petitioner suffered from impulse control disorders.69 In his [514] neuropsychological evaluation report dated August 7, 1996, he determined that the homicides were a “result of very complicated and powerful psychological and interpersonal factors which developed over many years, but were suddenly impulsively unleashed while in an intoxicated state.” He explained that Petitioner was “instantly flooded with angry emotion, a cauldron of stored up aggression was released, and he lost control.”70 In an addendum to his report dated January 2, 1997, Dr. Cripe stated that, after reviewing his evaluation and considering Edmon and other cases, he concluded that Petitioner suffered from a “severe antisocial personality disorder with episodic dyscontrol which is the result of complex biosocial-psychological causes.”71 But in that same report he also concluded that Petitioner suffers from “a mental illness related to a long history of child and adolescent abuse which combined with drug abuse and the circumstances of the homicides resulted in a diminished capacity to normally control his mind and behavior”.72 In a declaration dated July 28, 1997, Dr. Cripe[515] stated that “Mr. Ellis suffers from a severe personality disorder. There are mixed features to this personality disorder, but one of the features is antisocial. Additionally, he has an impulse control disorder. These disorders are the result of complex biological, social, and psychological factors.”73
The State contends Dr. Whitehill’s testimony was not based upon substantial supporting evidence in the record and he did not state an opinion with reasonable medical certainty as required under “Edmon factors” three and four.74
The State asserts that because the defense experts relied upon Petitioner’s “self-serving statements,” their opinions were grounded in speculation.75 Referring to Dr. Gripe’s testimony, the State claims he disregarded the fact that Petitioner contradicted himself in statements about using drugs and alcohol before the killings.76 The State argues that defense experts testified that Petitioner’s actions resulted from extreme “explosive rage” and “emotional flooding,” which describes an irresistible impulse, a defense not available in this State. The State concludes that consequently Petitioner has not satisfied “Edmon factor” five, which requires that the cause of the inability to form a specific intent must be a mental disorder, and not emotions like jealousy, fear, anger, and hatred.77
According to the State, Petitioner has not satisfied “Edmon factors” six, seven, eight, and nine because defense experts did not explain how Petitioner’s mental disorders caused an inability to form intent. The State claims the expert testimony was conclusory only and did not logically [516] and reasonably connect Petitioner’s alleged mental condition with the asserted inability to form the required specific intent to commit the crime charged. The State argues that, after being given another opportunity on the motion for reconsideration, Dr. Cripe could not reasonably and logically connect Petitioner’s mental disorders with lack of intent.78
The State contends this Court affirmed the trial court’s refusal to instruct the jury on diminished capacity on similar grounds in State v. Ferrick.79 In that case, the defendant, who was convicted of first degree murder, had been committed to and discharged from Western State Hospital three times. Shortly after her last discharge, the defendant stopped taking her prescribed medication and brutally stabbed her mother to death upon learning her mother had talked about having her recommitted. The Court concluded there was “no substantial evidence to establish that [defendant’s] alleged mental condition diminished or destroyed her capacity to form the specific intent to kill her mother.”80
The State asserts that defense experts in this case similarly did not provide the necessary nexus. The State noted that its expert, Dr. Gagliardi, testified that ideally the causal nexus between the disability and lack of intent requires either a scientific or very good clinical explanation and the disability has to relate to a relatively well-defined and very serious mental disorder and not a minor mental disorder or personality disorder.81
The State concludes that the trial court properly exercised its discretion in excluding Petitioner’s expert testimony on diminished capacity because Petitioner did not satisfy the nine foundational requirements of Edmon. The [517] State asserts that the court’s decision to exclude evidence may be “reversed only upon a manifest abuse of discretion” and “sustained on any proper basis within the record and will not be reversed simply because the trial court gave a wrong or insufficient reason for its determination.”82 The State gratuitously emphasizes that the court’s ruling would not preclude Petitioner from presenting diminished capacity testimony as mitigation evidence in the sentencing phase83 of the trial, in the event the case proceeds to that stage.
Petitioner argues that the expert testimony in this case has satisfied the foundational requirements of Edmon and that it is also admissible under Evidence Rule (ER) 702.84 According to Petitioner, in recent cases since Edmon this Court has held that ER 702 governs admissibility of expert testimony which does not involve new or novel scientific evidence. He asserts that diminished capacity is a well-recognized defense and does not involve new or novel scientific principles and therefore courts should allow expert testimony on diminished capacity when the requirements of ER 702 have been satisfied. Petitioner contends the qualifications of the defense experts were unchallenged and their testimony would be helpful to the trier of fact because mental disorders are beyond the ordinary understanding of lay persons. The State to the contrary asserts that because Petitioner did not argue ER 702 admissibility before the trial court, he is precluded from presenting that argument on appeal. This is not necessarily so. We accept Petitioner’s argument under the circumstances of this case.85
[518] The State argues that expert testimony on diminished capacity would not be admissible under ER 702, which is at most a general rule for admissibility of expert testimony. The State asserts that if this Court allows expert testimony on diminished capacity under ER 702, it would be overruling Edmon which requires a defendant to satisfy nine foundational requirements before presenting to the trier of fact expert testimony on diminished capacity.
Petitioner argues that the trial court’s ruling excluding his expert testimony, which precludes him from establishing diminished capacity in the guilt phase of his trial, deprives him of his constitutional right to present his own defense. He contends the United States Supreme Court has held that under the Fifth, Sixth, and Fourteenth amendments, criminal defendants have a constitutional right to testify in their own defense. Petitioner cites Rock v. Arkansas86 in which the Court stated that, although the right to present relevant testimony is not without limitation, “restrictions of a defendant’s right to testify may not be arbitrary or disproportionate to the purposes they are designed to serve. In applying its evidentiary rules a State must evaluate whether the interests served by a rule justify the limitation imposed on the defendant’s constitutional right to testify.”
Petitioner argues that, as a criminal defendant in a capital case, his constitutional right to present a defense outweighs any interest served by excluding his expert testimony. Petitioner suggests the State seems fearful that the jury might be influenced by the expert testimony and possibly acquit on the basis of irresistible impulse or mere emotion instead of diminished capacity. Petitioner asserts that actually a jury is not bound by the opinion of an expert and will properly evaluate the credibility of the testimony [519] under proper instructions from the court such as Washington Pattern Instruction (WPIC) 6.51.87
The State asserts the United States Supreme Court stated in Montana v. Egelhoff that “the proposition that the Due Process Clause guarantees the right to introduce all relevant evidence is simply indefensible. . . . The accused does not have an unfettered right to offer [evidence] that is incompetent, privileged, or otherwise inadmissible under standard rules of evidence.” In that case, the Court rejected a due process challenge to a state statute which precluded defendants from claiming diminished capacity occasioned by voluntary intoxication. The Court ruled it is “ ‘within the power of the State to regulate procedures under which its laws are carried out,’ . . . and its decision in this regard is not subject to proscription under the Due Process Clause unless ‘it offends some principle of justice so rooted in the traditions and conscience of our people as to be ranked as fundamental.’ ”88 The State contends Petitioner has not shown that his “right to present a diminished capacity defense” is a fundamental principle of justice and therefore neither Washington law on diminished capacity nor the ruling of the trial court is unconstitutional.
In reversing the trial court on allowing expert testimony on diminished capacity, the Court of Appeals in Edmon explained that “[t]he psychiatrist properly testified to a mental condition, i.e., reduced perception, that, in his opinion, was part of the mechanism flowing from the mental disorder and impairing Edmon’s ability to form the [520] intent to kill or injure. An opinion unsupported by this explanation would have been inadmissible.”89
In this case defense expert Dr. Whitehill testified that Petitioner suffered from a borderline personality disorder and intermittent explosive disorder. He explained these disorders underlay Petitioner’s killing of his mother because he misperceived her remarks about his girl friend and interpreted them as “extremely deflammatory [sic], as denying him his self. There would be some diminished ego function there, and then the capper, of course, is the reaction to the interpretation. This is what I have termed emotional discontrol. ... So we have an individual whose perceptional process, whose interpreting process, his decision making capacity and his ability to properly regulate his behavior, was severely compromised as a direct result of this ongoing personality disturbance.” Dr. Whitehill testified that in Petitioner’s “continuously disregulated state” he killed his sister because he believed “that this was a child who symbolized all of what he did not receive with respect to maternal attachment, all of what Jamie, his young sister received. . . . [s]he awakened as a stimulus, someone which reminded him, which triggered another intense exacerbation of an already existing level of emotional dis-control.”
Defense expert Dr. Cripe testified that Petitioner suffered from an antisocial personality disorder and impulse control disorder. When asked by defense counsel how the mental disorder causally connected to lack of intent, Dr. Cripe responded that “when he went over there in that situation with his mother, he walked in there with this history of problems, this history of mental disorder. . . . He is in a situation where certain stressors arise. And given the weaknesses in his psychological makeup, the mind is overpowered basically by—there is a breakdown in the deliberation process, in forming judgments and decisions, [521] and the person ends up acting from disarray and from confusion and emotional forces, rather than from a deliberate forming of intent. . . .” Dr. Cripe stated that he believed Petitioner did not act with intent partly because “it’s not very common that human beings kill their mothers and little sisters. This is an extraordinary thing. ... I mean people who plan and deliberately kill people, like hit men, don’t do it with breadboards.”
The trial court in this case intelligently evaluated the testimony and reports of defense expert witnesses. The court, however, placed too much reliance upon foundational criteria announced in State v. Edmon, a 1981 Court of Appeals case. We do not consider Edmon controlling in this case. Strict application of Edmon results in at least a questionable result in this capital case by depriving Petitioner Ellis, before trial, of an opportunity to present a diminished capacity defense. The question of admissibility of the testimony of defense experts is better determined under ER 702, 401 and 402.90 If at trial the court allows any such testimony, its weight and value would then be determined by the trier of fact, the jury, under proper instructions, including an instruction such as WPIC 6.51.
SUMMARY AND CONCLUSION
To maintain a diminished capacity defense, a defendant must produce expert testimony demonstrating that a mental disorder, not amounting to insanity, impaired the defendant’s ability to form the specific intent to commit the crime charged.
Considering the defense expert testimony in its entirety, the trial court correctly determined the foundational [522] requirements for admitting expert testimony on diminished capacity as announced in the 1981 Court of Appeals case of State v. Edmon91 had not been satisfied. But we do not consider that case controlling in our decision in this case.
For some reason, not quite evident, the 1981 Court of Appeals decision, State v. Edmons, has been elevated to the status of the last, absolute and definitive word on foundational requirements for presentation or admissibility of expert testimony on diminished capacity. In fact the nine foundational requirements the opinion states must be satisfied before “[a]n expert may give an opinion regarding a defendant’s ability to form a specific intent” have been referred to as “Edmon factors.” Petitioner Ellis and Respondent State both address their primary attention to whether the nine “Edmon factors” have been satisfied. The trial court judge made her decision by strict application of the “Edmon factors.”
We do not adopt the foundational requirements announced in Edmon as absolute. Even assuming their applicability in this case, it was error for the trial court to exclude the proffered defense expert testimony on diminished capacity prior to trial on a motion in limine in this case which is an aggravated first degree murder case in which the State intends to ask for the death penalty. There is sufficient basis in the record at this stage to allow expert testimony on diminished capacity at trial during the guilt phase.
The defense expert witnesses—all qualified to give opinions—will testify that Petitioner Ellis experienced diminished capacity at the time he committed the offenses [523] charged. Their testimony should be allowed at trial under ER 702. They would be subject to cross-examination as they were as “hostile witnesses” in the pretrial proceeding on the motion in limine. The trier of fact—the jury—can then determine what weight, if any, it will give to their testimony. This is fundamentally fair and consistent with due process.
Evidence Rule 702 states the general rule for admissibility of expert testimony, although it does not refer specifically to expert opinion on diminished capacity. The decision of the trial court to exclude expert testimony on diminished capacity prior to trial upon the record before us deprives Petitioner Ellis of his constitutional right to present evidence in his defense, notwithstanding the trial court’s understandable interpretation of State v. Edmon.
“Admissibility of evidence lies within the sound discretion of the trial court and the court’s decision will not be reversed absent abuse of that discretion.”92 “An abuse of discretion occurs only when no reasonable person would take the view adopted by the trial court.”93 Under the circumstances of this case, a pretrial proceeding in a capital case, the abuse of discretion rule must be applied in order to achieve a fundamentally fair result. In excluding the expert testimony on diminished capacity in the State’s motion in limine, the court unreasonably and prematurely concluded the foundation for admissibility had not been satisfied. The court should have considered admissibility under ER 702 and application of ER 401 and 402.
We reverse the Superior Court and allow Petitioner Joey C. Ellis to proceed with presentation of expert testimony in the guilt phase of his case to establish his diminished capacity defense subject to admissibility under Evidence Rule 702 and subject to appropriate instructions to the jury.
Dolliver, Johnson, Madsen, and Sanders, JJ., concur.