Does a court have to instruct a jury on the weight of expert testimony?

Section 1127b requires a trial court to instruct sua sponte on the weight of expert testimony whenever it admits expert opinion into evidence in a criminal proceeding.⁴ The failure to so instruct is not prejudicial "unless the reviewing court, upon an examination of the entire cause, determines that the jury might have rendered a different verdict had the omitted instruction been given." (People v. Reeder (1976) 65 Cal.App.3d 235, 241.) In this matter, the trial court admitted expert testimony but failed to instruct the jury as required by section 1127b. Based on our review of the record, we conclude the error was not prejudicial.

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