What is the test for bifurcation in a criminal case?

Finally, the bifurcation procedure would not impair the prosecution's case. The procedure would be available only when other-crimes evidence, inadmissible as to guilt, is offered in support of a special circumstance allegation. Just as the prosecution may not withhold a stipulation as to the ex-felon status of an accused in a prosecution for possession of a firearm unless the stipulation would legitimately impair its case (People v. Hall (1980) 28 Cal.3d 143, 156-157, 167 Cal.Rptr. 844, 616 P.2d 826), it may not place evidence before a jury at a stage where such evidence has no admissible purpose.

A bifurcation procedure has been adopted in an analogous context. In People v. Bracamonte, supra, 119 Cal.App.3d 644, 174 Cal.Rptr. 191, the court held that an accused is entitled, upon request, to a bifurcated proceeding on the truth of prior convictions which have been alleged for the purpose of enhancing the sentence. Such a [691 P.2d 1012] rule was found to be appropriate in view of (1) the high potential for prejudice inherent in evidence of prior criminal activity, and (2) the absence of practical obstacles which might require a unitary procedure. (Id., at pp. 651-655, 174 Cal.Rptr. 191.) That court's reasoning is applicable in the present context.