The courts currently send criminal defendants away, sometimes for the rest of their lives, on the basis of "gang expert" testimony about how a defendant would behave in certain circumstances because he is a gang member. ( People v. Gardeley (1996) 14 Cal. 4th 605, 617-620, 927 P.2d 713 [expert testimony concerning the culture, habits and psychology of gangs is permissible because these subjects are sufficiently beyond common experience the opinion of an expert would assist the trier of fact]; People v. Valdez (1997) 58 Cal. App. 4th 494, 507 [in murder prosecution in which gang enhancement was alleged, police officer was allowed to give expert opinion on whether the defendant acted for the benefit of a criminal street gang]; see also, 1 Witkin, Cal. Evidence (3d ed. 1999 supp.The Opinion Rule, 533, p. 210.)