Changes in admissibility of evidence do not violate the proscription against ex post facto application of laws. In 1994, appellant fatally shot the mother of his child, a woman with whom he had previously been involved, and shot and wounded her male companion. Appellant fled to Mexico, but returned to the United States in 2006, and was prosecuted for the crimes in 2007. At a first trial he was convicted of attempted premeditated murder of the male, and in a second trial which followed a mistrial, he was convicted of first degree murder of the woman. At this trial, evidence was introduced pursuant to Evidence Code section 1109 that he had previously been convicted of misdemeanor spousal battery against a separate individual. Section 1109 had been enacted after the murder. The court gave CALCRIM No. 852, instructing the evidence could not be used as proof of the instant crime, but that the jury could only conclude from it that defendant was predisposed to domestic violence. The appellate court rejected appellant’s claim that admitting the evidence violated the prohibition against ex post facto laws – specifically, that it altered the legal rules of evidence resulting in order to convict the offender. Although the government is barred from changing rules involving the legal sufficiency of evidence, ex post facto principles do not bear on the admissibility of a particular piece of evidence bearing upon a particular fact to be proved. (People v. Brown (2004) 33 Cal.4th 382.)