Is there any case law supporting the proposition that expert testimony on whether a defendant acted for the benefit of a gang is permissible?

Defendant also claims People v. Valdez, supra, 58 Cal.App.4th at p. 508 stands for the proposition that expert testimony on whether the defendant acted for the benefit of a gang "is permissible only if the situation is so complicated that expert opinion on the subject is necessary." Valdez did not say that. Valdez involved a group of people from different gangs who came together one day to attack another gang. Given these unique facts, the court concluded "the questions of how such a diverse group . . . could have been acting for the benefit of a street gang and whether the participants were doing so presented matters far beyond the common experience of the jury and justified expert testimony." (Id. at pp. 508-509.)