In what circumstances will a court allow a defendant to plead guilty to a charge of perverting the course of justice by admitting that he had a fascination with knives?

In McKinney v. Rees, we addressed the circumstances under which the admission of character evidence violates due process. In that case, the victim-the defendant's mother-died after her throat was slit. 993 F.2d at 1381. The prosecution introduced a litany of evidence regarding the defendant's apparent "fascination" with knives. Id. at 1382. For example, the court admitted evidence that the defendant was proud of his knife collection, that he had on occasion strapped a knife to his body while wearing camouflage pants, and that he had used a knife to scratch the words "Death is His" on a door in his dormitory room. Id. We held that because this evidence was not offered to prove opportunity, but rather was an "impermissible propensity inference based on other acts offered to prove character," it was erroneously admitted by the trial court. Id. at 1383; see also id. at 1383 n.6.