State v. Romero, 730 Ariz. Adv. Rep. 4 (January 20, 2016) (C.J. Bales)
PARTY MAY OFFER EXPERT IN FIELD OTHER THAN OPPONENT'S AREA OF EXPERTISE
The defendant was convicted of second degree murder based in part upon the government's firearms expert testimony matching toolmarks on shell casings with the defendant's handgun. The trial court conducted a Daubert hearing finding the government's expert qualified to testify but precluding Defendant's expert based upon Rule 702 R. Evid. The Arizona Supreme Court vacated the trial court's ruling precluding the testimony of defendant's expert and remanded.
The trial court found that defendant's expert had no prior experience testifying as to firearms identification, had never conducted tool mark analysis or researched firearm's identification and therefore was unqualified to testify. The supreme court disagreed noting that defendant's expert was never held out as a firearm's expert but rather an experimental design expert—his testimony was proffered to help the jury understand how the methods used by firearms examiners in performing toolmark analysis differ from the scientific methods generally employed in designing experiments. In essence his testimony attacked the government expert's methodology and therefore the weight his testimony should be given. His qualifications as a “design expert” were more than adequate.
Under Rule 702 . . . the opposing party is not restricted to challenging that expert by offering an expert from the same field or with the same qualifications. The trial court should not assess whether the opposing party's expert is as qualified as – or more convincing than – the other expert. Instead, the court should consider whether the proffered expert is qualified and will offer reliable testimony that is helpful to the jury.
Close questions should be decided in favor of allowing the testimony. Here defendant's expert attacked the weight the testimony of the government's firearms examiner should be given. The weight to be given testimony is always for the jury.
Finally, the trial court improperly excluded defendant's expert on the secondary basis that to allow the testimony would essentially result in a second Daubert hearing. The court had already decided that the government's expert methodology and conclusions were sufficiently reliable thus finding it would be improper to allow the jury to overrule the court on this question. The supreme court held that the question of the weight and credibility are always jury questions, prior Daubert hearing or not.
The case was remanded to the Arizona Court of Appeals with direction it decide whether the preclusion of the defendant's expert testimony was harmless error.