Judge Committed Multiple Errors Related to Expert Witness Testimony

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A Monterey County jury convicted Brad Azcona of two premeditated murders, two attempted murders, three assaults with a deadly weapon, negligently discharging and possessing a firearm, and attempted robbery. The jury also found true the special circumstance allegation that Mr. Azcona committed multiple murders. Mr. Azcona was sentenced to life without parole, consecutive to a term of 156 years four months.

The Court of Appeal reversed the judgment on three counts.

The Court of Appeal concluded “the trial court committed multiple errors related to the firearms expert testimony. Abandoning its gatekeeping responsibility, the court allowed the expert to testify to conclusions not supported by the material on which he relied. (The court also violated Mr. Azcona’s 6th Amendment right to confrontation by allowing the expert to testify that his findings were reviewed and approved by a supervisor, however, that is not discussed in this article.)

The trial court denied Mr. Azcona’s motion in limine to exclude expert testimony about firearm toolmark comparison. Mr. Azcona claimed the method used – visually comparing marks on the casings—was not generally accepted by the scientific community, as required under People v. Kelly (1976) 17 Cal.3d 24. 510.

The “generally accepted in the scientific community” standard:

“Expert testimony based on the application of a scientific technique is admissible in California if the technique is generally accepted in the pertinent scientific community.” People v. Kelly, supra, 17 Cal.3d 24, 32.

“General acceptance means “a consensus drawn from a typical cross-section of the relevant, qualified scientific community.” People v. Leahy (1994) 8 Cal.4th 587, 612.

“Unanimous acceptance is not required; “‘[r]ather, the test is met if use of the technique is supported by a clear majority of the members of that community.’” Ibid.

“That test has been criticized as essentially delegating admissibility to scientists without a judge directly confronting the reliability of the evidence. (Id., at p. 602.) But the Supreme Court has continued to endorse the Kelly standard, reasoning that “it may be preferable to let admissibility questions regarding new scientific techniques be settled by those persons most qualified to assess their validity.” Ibid.

“Defendant does not contend that visual comparison of toolmarks on bullet casings has yet to be generally accepted as reliable. He instead asserts that the technique’s validity has been recently undermined to such a degree that it is no longer admissible.”

“When the continuing admissibility of scientific evidence is at issue, rather than it being the proponent’s burden to show the technique is generally accepted by the scientific community, the burden shifts to the opposing party to produce new evidence showing it no longer is.”

“It is not clear that the technique employed here is subject to the Kelly standard at all, as visual comparison of marks on physical objects is not so foreign to everyday experience that jurors would have unusual difficulty evaluating it.”

“As the California Supreme Court observed in People v. Cowan (2010) 50 Cal.4th 401, regarding a similar method of firearm toolmark examination, the Kelly rule is “‘intended to prevent lay jurors from being unduly influenced by procedures which seem scientific and infallible, but which actually are not,’” and does not apply to such things as fingerprint, shoe track, or ballistics comparisons “‘which jurors essentially can see for themselves.’” Id., at p. 470.

“[E]ven if we assume for purposes of our analysis that firearm toolmark comparison is subject to Kelly principles, we cannot find the method categorically inadmissible here because defendant did not meet his burden to show that a clear majority of the relevant scientific community no longer accepts the method as reliable.”

“Defendant neither established what the relevant scientific community is, nor that a clear majority of that community now rejects ballistics comparison as unreliable.”

“Defendant focused in the trial court, as he does here, on attacking the reliability of the method itself. But it is not for the court to determine whether the method is reliable (in contrast to what a federal court would do under the Daubert standard). The necessary inquiry under Kelly is whether most of the relevant scientific community thinks it is.”

Because Mr. Azcona did not provide enough evidence to show firearm toolmark comparison is no longer accepted by a clear majority of the relevant scientific community, the Court of Appeal was unable to rule that expert testimony on that subject is no longer admissible in California.

Kelly Not Applicable, But Court Abandoned Its Gatekeeping Role

However, the Court of Appeal, noted, “Trial judges have a critical gatekeeping function when it comes to expert testimony beyond merely determining whether the expert may testify at all.”

“Expert evidence that does not require a Kelly analysis must still be admissible under Evidence Code section 801, which mandates it be ‘of a type that reasonably may be relied upon by an expert in forming an opinion upon the subject.’” Evid. Code, § 801, subd.(b); see In re O.D. (2013) 221 Cal.App.4th 1001, 1009.

“Further, under Evidence Code sections 801, subdivision (b), and 802, the court must act as a gatekeeper to ensure the opinions offered by an expert are not “based on reasons unsupported by the material on which the expert relies.” Sargon Enterprises, Inc. v. University of Southern California (2012) 55 Cal.4th 747, 771.

“This means that a court may inquire into, not only the type of material on which an expert relies, but also whether that material actually supports the expert’s reasoning. ‘A court may conclude that there is simply too great an analytical gap between the data and the opinion proffered.’” Ibid.

“A trial court’s duty to keep unfounded opinions from the jury is particularly important in a situation like the one presented here, where significant criticism of the expert’s methodology was presented (even if it was not shown to have been rejected by a clear majority of the scientific community).”

“The existence of such criticism should prompt a trial court to carefully determine what conclusions can reliably be drawn from the methodology in question. But here the trial court abandoned its gatekeeping role, allowing unfettered expert testimony that went far beyond what the underlying material supported.”

The Court of Appeal reversed the judgment on three of the counts, ruling that “[t]he trial court abused its discretion by failing to limit the expert’s opinion to what was actually supported by the material the expert relied on.”

This opinion can be found at People v. Azcona (2020) 58 Cal. App. 5th 504.


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