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Name: People v. Rouston (2024) 99 Cal.App.5th 997
Case #: D080114
Court: CA Court of Appeal
District 4 DCA
Division: 1
Opinion Date: 02/20/2024

Trial court prejudicially erred in permitting prosecution’s gang expert witness to opine on whether appellant fired the bullet that struck the victim where that opinion was based solely on the claims of percipient witnesses and relied on no special expertise. The prosecution’s gang expert testified multiple times throughout the trial, telling the jury that each witness’s testimony bolstered his opinion that Rouston was holding a particular firearm, that the firearm was the first fired in the incident, and that the first shot was the one that struck the victim. On appeal, Rouston argued, inter alia, that this testimony was improper because it usurped the role of the jury. Held: Reversed. Expert testimony is admissible only if it is “[r]elated to a subject sufficiently beyond common experience that the opinion . . . would assist the trier of fact.” (Evid. Code, § 801.) The expert’s opinion here that Rouston fired the shot in question was based solely on the testimony of the witness who made that claim. This inference required no expertise and supplanted the jury’s role in weighing evidence and determining what the facts were. Without the expert’s improper testimony that Rouston fired the shot that struck the victim, there is a reasonable probability the jury would have reached a different result based on the evidence in this case. [Editor’s Note: (1) The court also cited with approval federal cases holding expert witnesses should not be called to provide overviews or summaries of the prosecution case and cases cautioning against permitting police officers to testify as both percipient and expert witnesses without careful instructions to avoid confusion. (2) The court also concluded Rouston forfeited his objections to the officer’s testimony based on lack of expertise.]