Is evidence of bad acts or uncharged crimes or bad acts inadmissible in a criminal case?

[23 Cal.App.4th 1077] Evidence of a defendant's prior bad acts or uncharged crimes is inadmissible to show he had the criminal propensity to commit the crime charged. (Evid.Code, 1101, subd. (a); People v. Scott (1987) 194 Cal.App.3d 550, 552-556, 239 Cal.Rptr. 588.) However, Evidence Code section 1101, subdivision (b) permits admission of prior "bad acts" if relevant to resolving an issue in the case or to prove some fact such as motive, opportunity, intent, preparation, plan, knowledge, identity or absence of mistake.