Bill Cosby, the lustful disposition exception, and the doctrine of chances.

Author:Oliver, Wesley M.

On December 30, 2015, an affidavit of probable cause alleged that William H. Cosby, Jr., Ed.D., a comedian whose storied career spanned decades, committed aggravated indecent sexual assault upon Andrea Constand. (1) For decades, women have been coming forward claiming to have been the victims of Cosby's unwanted sexual advances, most of them claiming that Cosby drugged them and took advantage of them when they were in an unconscious state. (2) Despite the number of accusers over decades, thus far only one criminal count has been announced. At this point, it appears that the statute of limitation would preclude an indictment charging any criminal acts against the other alleged victims.

That does not mean that we have heard the last of the other accusers. Even though evidence of a defendant's bad character is "not admissible for the purpose of proving the person acted in conformity therewith," (3) common sense would dictate that a trier of fact should hear from the other victims who claim Cosby similarly assaulted them.

What are the odds that one man could be falsely accused by fifty women? A few courts have asked exactly this question using something called the doctrine of chances, a rule that expressly considers the likelihood that the defendant is innocent of the present offense in light of what we know about his past. Rather than conducting such an analysis, however, a number of courts tend to merely admit all prior sexual misconduct under what is known as the lustful disposition exception. A number of other courts, such a those in Pennsylvania where Cosby will be tried, liberally admit prior sexual misconduct evidence to show that the defendant's actions in question were consistent with a plan.

Prior sexual misconduct, however, is no more likely than other types of bad acts to predict future misconduct. Because courts more readily admit prior acts to predict future conduct when the acts are of a sexual nature, it seems likely that Cosby's other accusers will be allowed to testify. The result in this case seems correct, but the logic is certainly questionable.

If fifty store clerks had come forward and accused Bill Cosby of petty larceny, their testimony would powerfully undermine his claims of innocence in a shoplifting trial. The power of the testimony of Cosby's other accusers lies in the number of similar accusations, not the fact that all the accusations involve sexual misconduct. Courts, however, tend to ask whether the uncharged acts fit into a defined category in deciding whether to admit this sort of otherwise inadmissible character evidence. Courts do not usually critically ask about the value of the other alleged misdeeds in determining the disputed facts. The testimony of fifty other larceny victims is therefore generally not admissible, but the testimony of one other rape victim often is.

For the wrong reasons, the law is likely to arrive at the right answer in the Cosby case.


    It is difficult to explain to a non-lawyer why a defendant's prior bad acts generally cannot be used to determine whether he committed the criminal act with which he is charged. It is generally accepted that previous criminal conduct increases the odds that the defendant engaged in subsequent criminal conduct. (4) This is just common sense. The prohibition on character evidence is therefore often justified by a concern that the jury will over-rely on the probative weight of his prior bad acts, giving them more weight than they deserve, not that a defendant's character has no relevance in assessing his guilt. (5) An extreme version of this concern is that a defendant may be convicted because of his past alone. (6) If the admission of a defendant's prior bad acts has the potential to work this sort of mischief, then it is difficult to explain anything other than the rare and exceptional admission of such evidence. Yet, the rules of evidence allow bad acts to be admitted somewhat commonly.

    While evidence codes prohibit the use of a defendant's character to show that he committed the act in question, the drafters of the rules hedged their bets with a litany of exceptions. The Federal Rules of Evidence, largely adopted by most states, (7) provide that "[e]vidence of a crime, wrong, or other act is not admissible to prove a person's character in order to show that on a particular occasion the person acted in accordance with the character." (8) But in the next provision, these same rules provide that "[t]his evidence may be admissible for another purpose, such as proving motive, opportunity, intent, preparation, plan, knowledge, identity, absence of mistake, or lack of accident." (9)

    Character evidence is thus governed by a contradiction. The rules of evidence essentially say evidence of a defendant's propensity to commit bad acts cannot be used to show that he committed a bad act on a particular occasion. But a defendant's propensity to have a particular intent, (10) for instance, can be used to demonstrate that he possessed that intent on a particular occasion.

    In a classic case, a postal carrier was accused of stealing a silver dollar from his mail route. (11) To rebut a claim that he had no intention of keeping the coin, the prosecution introduced credit cards belonging to others on his mail route that were found in his wallet at the time of his arrest. (12) Doctrinally, courts reason that such testimony is admissible because it is offered not to prove the defendant's propensity to commit theft, but as evidence demonstrating the defendant's intent to permanently deprive the rightful owner of the coin mailed to him. In other words, the prosecution is permitted to introduce evidence of the defendant's propensity to possess the intent to permanently deprive, but not evidence of the defendant's propensity to steal. The distinction is difficult to grasp even for people who parse such language for a living.

    The exceptions certainly do not limit character evidence to prior acts that show an individual's intent. The rules of evidence permit prosecutors, in a variety of circumstances, to use the past to predict the future, so long as the particular type of prediction is identified in the rule. If the past is used to suggest that in the future the defendant had knowledge or motive, the evidence is admissible to show the defendant's mental state (i.e., his mens red). (13) Prior bad acts are also admissible to show actus reus--to show that the defendant actually committed the act in question. Otherwise inadmissible character evidence may be offered to show identity or common plan. (14) Contrary to the prohibition in the evidentiary rules on admitting evidence to show a defendant's propensity, the rules governing character evidence very much permit proof of...

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