In our view, the use of the defendant's prior bad acts to ostensibly prove his motive for entering the bedroom here is a dangerously short step away from simply using prior bad acts to prove his motive for committing the current, virtually identical, bad act. A prosecutor might argue: "We know his motive for going to her room that night was to sodomize her–because the evidence shows that he had sodomized her in this same house, perhaps in this same room, on prior occasions." Indeed, the language chosen by the State comes close to making this very argument in the instant case.
. . . .
Conviction for mere "propensity"–defined by The American Heritage Dictionary of the English Language 1048 (1971), as an innate inclination, a tendency or bent–would be the almost certain result of admitting this evidence for motive. If this evidentiary admission practice were approved, prosecutors would understandably begin pressing trial courts for admission of all other past bad acts of a defendant to serve as motive for his or her present charges, especially when any degree of similarity existed.
Similarly, the KSC analyzed "intent" as a potential material disputed fact:
If the defendant admits the conduct but offers an "innocent" explanation, the Dotson court suggests the evidence of other crimes is admissible on intent. But if, as in Dotson, the defendant admits the conduct and offers no explanation, and no inference can be drawn regarding the innocence of the conduct, the evidence is not admissible on intent. When a defendant wholly denies committing the alleged acts, admitting evidence of prior bad acts to prove intent is error.
. . . .
Here, the disputed fact is whether Wells touched C.B., not Wells' purpose in entering her bedroom. He completely denies any touching. Therefore, intent was not a disputed material fact in the crime of aggravated criminal sodomy.
Because neither "motive" nor "intent" were disputed material facts, the KSC held the prior bad act evidence was improperly admitted in the trial. Also, because of the lack of physical corroborating evidence, the KSC held that the improper admission was prejudicial and ordered a new trial.