What is the test for admissibility of evidence of past misconduct in a criminal case?

Four factors are considered when analyzing whether prior acts are more prejudicial than probative: "(1) the inflammatory nature of the uncharged conduct; (2) the possibility of confusion of issues; (3) remoteness in time of the uncharged offenses; and (4) the amount of time involved in introducing and refuting the evidence of uncharged offenses." (People v. Branch (2001) 91 Cal.App.4th 274, 282, citing People v. Harris (1998) 60 Cal.App.4th 727, 737-741.)

Our high court has cautioned that the admission of evidence involving a defendant's prior crimes has an inflammatory and prejudicial impact on a jury, and such evidence produces a very strong tendency to believe that the defendant is guilty of the charge merely because he is likely to do such acts. (People v. Holt (1984) 37 Cal.3d 436, 450-451.) As a result, evidence of prior specific acts of misconduct is ordinarily inadmissible to attack a witness's credibility. (Id. at p. 451.) Where such evidence is relevant for another purpose, a trial court should receive it " 'with "extreme caution," its admissibility "examined with care," and in the event of uncertainty as to its connection with the offense charged "the doubt should be resolved in favor of the accused." ' " (Ibid.)