Comparison to prior conviction allegations is useful but limited because a prior conviction involves a single discrete fact. Once the fact of the prior conviction becomes known to the jury, there is no longer any reason to try the prior conviction allegation separately. Proof of a criminal street gang enhancement, unlike a prior conviction allegation, involves an array of facts, many of which are irrelevant to proof of the underlying offense. Accordingly, in ruling on a motion for bifurcation of a criminal street gang enhancement, the better approach would be to weigh and consider all the relevant factors before determining whether a unitary trial of the offense and the enhancement is consistent with the defendant’s right to a fair trial.
A more reasoned paradigm for the exercise of a trial court’s discretion is found in the criteria applied in ruling on a motion for severance. The Supreme Court in Williams v. Superior Court (1984) 36 Cal.3d 441, 448-450, established four principal criteria for evaluating a claim of prejudice from the denial of a severance motion: (1) whether evidence of the joined charges is cross-admissible; (2) whether the joined charges are of such a nature that one or more of them is so inflammatory as to prejudice the jury’s consideration of the remaining charge or charges; (3) whether a weak charge has been joined with a stronger case that provides “spillover” strength to the weak charge; and, (4) whether one of the charges is a capital offense, or the joinder of the charges converts the matter into a capital case. 5 (People v. Balderas (1985) 41 Cal.3d 144, 173; accord People v. Mendoza (2000) 24 Cal.4th 130, 161; Frank v. Superior Court (1989) 48 Cal.3d 632, 638-639.) Application of these criteria is a “highly individualized exercise, necessarily dependent upon the particular circumstances of each individual case.” (Williams v. Superior Court, supra, 36 Cal.3d at p. 452.)
The first factor, cross-admissibility of evidence, is most significant because, if gang enhancement evidence would have been admissible in a separate trial on the underlying charges, “ ‘ “any inference of prejudice is dispelled.” ’ ” (People v.
5 The death penalty was not sought in this case and thus is not an applicable factor here.