State v. Bernstein (Herman)
A plain-English summary from Criminal Defense Resources™, a free resource for pro per/pro se defendants and their families.
- Decided
- Citation
- 237 Ariz. 226 (2015)
What did the court decide?
In a special action brought by the State in eleven aggravated DUI cases (the real parties were Doreen Lynn Herman and ten other defendants), the Arizona Supreme Court held that under Arizona Rule of Evidence 702(d), the trial judge, as gatekeeper, must consider whether an expert correctly applied a reliable method to the facts of the case. But mistakes in applying a method justify excluding the evidence only if they make the results themselves unreliable; otherwise the jury weighs them. The trial judge had excluded blood-alcohol results because the lab's gas chromatograph sometimes failed to produce results and had other problems. The Supreme Court said that applied the wrong standard, because the record did not show the defendants' own results were unreliable, and vacated the exclusion order.
Why does it matter?
This is the main Arizona case on challenging how an expert or lab applied its method, and the same rule applies to State experts and defense experts. Instrument problems that do not justify exclusion can still be raised with the jury through cross-examination and contrary evidence. Arizona's Rule 702 has followed the federal Daubert approach since January 1, 2012, and was amended again effective January 1, 2024 to match a 2023 change to the federal rule.
Where can I read the full opinion?
Read the full opinion on Arizona Judicial Branch →
Always read the full opinion and check whether later cases have limited or changed it. A summary can leave out important details.
Related rulings
- Daubert v. Merrell Dow Pharmaceuticals, Inc.
- Frye v. United States
- State v. Schoenhardt
- United States v. Valencia-Lopez