Is there a need for severance or separate juries for multiple defendants?

We recently considered the very issue defendant raises regarding the need for severance or separate juries for multiple defendants. In People v. Ervin (2000) 22 Cal.4th 48, 69, 91 Cal.Rptr.2d 623, 990 P.2d 506, we observed, "We have held that, in light of the statutory preference for joint trials (see 1098), severance remains largely within the trial court's discretion. [Citations.] Nonetheless, we have also stated that a reviewing court may reverse a conviction when, because of consolidation, '"gross unfairness"` has deprived the defendant of a fair trial. [Citation.] The record in the present case, however, fails to show that the jurors in this joint trial were unable or unwilling to assess independently the respective culpability of each codefendant or were confused by the limiting instructions." In Ervin, we rejected the defendant's claim that the court should have ordered separate guilt and penalty trials for each defendant. (Ibid. [guilt phase]; id. at pp. 95-96, 91 Cal. Rptr.2d 623, 990 P.2d 506 [penalty phase].)