(concurring in majority) — I agree with the majority that trial court decisions to admit or exclude expert testimony are reviewed for an abuse of discretion. I further agree that under the facts of this case, we cannot say that the trial court abused its discretion when it found Dr. Loftus’s testimony unhelpful and therefore inadmissible under evidence rule (ER) 702. I write separately to emphasize that, under our rules of evidence, a trial court has discretion to admit, and should admit, relevant expert testimony if it finds that the testimony will assist the trier of fact. Accordingly, read properly, the majority opinion does not bar the admission of expert testimony regarding eyewitness memory and perception, nor does it hold it would have been an abuse of discretion to admit Dr. Loftus’s testimony.
I agree with the dissent’s concluding statement of the law: “the trial court has no discretion outside the rules of evidence to refuse [relevant and competent evidence].” Dissent at 666 (emphasis added). We have continually held that the trial court may exclude expert testimony under ER 702 when it finds the proffered testimony will not be helpful to the trier of fact. State v. Swan, 114 Wn.2d 613, 656, 790 P.2d 610 (1990); State v. Mak, 105 Wn.2d 692, 715, 718 P.2d *656407 (1986); see State v. Allery, 101 Wn.2d 591, 597, 682 P.2d 312 (1984). The issue before us is not whether the expert testimony was relevant. Contra dissent at 665. Rather, the question we must answer is whether, in this instance, the trial court abused its discretion to exclude relevant testimony under ER 702.
I agree with both the majority’s and the dissent’s recognition that over the past two decades research has shed light onto the issue of eyewitness reliability. Majority at 645-46; dissent at 664-65. Further, I agree that illumination of eyewitness perception and memory by research is not necessarily within the common knowledge, experience, and understanding of the average juror. Majority at 646, 649 n.5. Moreover, I agree with the majority that it is unnecessary for an expert to have interviewed or tested the eyewitness. Majority at 649 n.5. However, an expert must give opinions specific to the facts of the particular case rather than testify about generalities. Finally, I am inclined to think that expert testimony regarding the effects of stress, violence, weapon focus, lighting, and cross-racial identification on eyewitness perception and memory would assist the trier of fact when, as here, the witness had approximately five seconds to view an armed attacker of a different race in the dark.
However, it is not this court’s duty to supplant the trial court’s discretion with our own. We noted long ago that trial courts must be afforded an amount of discretion in these matters because the line between that which is helpful and that which is unhelpful cannot be “very accurately drawn.” State v. Smails, 63 Wash. 172, 179, 115 P. 82 (1911).
The line of demarcation between matters that fall within the knowledge of mankind generally and matters that are the subject of special and peculiar knowledge cannot, from the nature of things, be very accurately drawn. The one, of necessity, shades into the other, and hence, even though the extremes of the opposing rules may be definitely marked and error predicated thereon easy of determination, the trial judge must have something of discretion whether he will or will not *657admit opinion evidence when the line of demarcation between these rules is approached.
Id. I emphasize that our opinion today rests largely on the trial court’s actual exercise of discretion. It also could have been an appropriate exercise of discretion under ER 702 for the trial court to find Dr. Loftus’s expert testimony helpful and admissible, as the first trial court to consider the issue did. Accordingly, I concur with the majority.