Everyone is entitled to the benefit of the doubt, no matter how heinous their crimes. Documented false rape accusations are uncommon, but they do occur, and defendants are entitled to challenge the allegations and the evidence against them if they choose. 

In this instance, Richard Jackson did not elect to do so. Given some of Richard Jackson's preparatory actions, such as transferring assets to his wife, and his willingness to plead guilty and accept what is likely to be effectively a life sentence for a man of his age, it is reasonable to believe that he committed the crimes in question. Courts generally do not make the lurid details public in such cases, and for good reason.