[Published Opinion] In a case in which appellant was charged with committing two unrelated murders (the Oakland and Hayward murders), the Court of Appeal found that the trial court abused its discretion in denying appellant’s motion for a mistrial after the jury was allowed to hear inadmissible evidence regarding the Oakland murder in the Hayward murder case. In reaching this decision, the Court found that the trial court’s admonishment was inadequate to cure the prejudice, especially considering that the success of appellant’s defense depended largely on the jury accepting his credibility when he testified —credibility that was surely damaged by evidence this was not the first time he shot and killed an unarmed man for no apparent reason.