Evidence of prior sexual offenses against a co-worker was properly admitted in trial for battery on an institutionalized victim. Manning was charged with battery on an institutionalized person in violation of Penal Code section 243.4, subdivision (b), for fondling patients in the hospital where he worked. At his trial, he moved to exclude evidence of a 1995 conviction for battery of a nurse. The evidence was admitted under Evidence Code section 1108. On appeal, Manning challenged the constitutionality of section 1108. The appellate court rejected the argument. Appellant also contended that the trial court erred in excluding expert testimony on the meaning of a West plea. (The prior conviction was the result of a no contest plea pursuant to People v. West (1970) 3 Cal.3d 595.) The appellate court found no error. The trial court properly excluded the evidence because it was irrelevant and would confuse the jury.