What is the test for admitting expert testimony in a criminal case?

A party may offer expert testimony related to a subject that is sufficiently beyond common experience such that the expert's opinion would assist the jury in evaluating the remaining evidence presented at trial. (Evid. Code, 801, subd. (a).) A trial court has broad discretion in deciding whether to admit an expert's testimony, and its ruling will be deemed error on appeal only when the record demonstrates an abuse of discretion. (See, e.g., People v. Page (1991) 2 Cal.App.4th 161, 187 (Page) [expert opinion on false confessions held properly excluded].)

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