Bill Cosby and the Rule Against Character Evidence


Bill Cosby, a formerly beloved comedian and actor, has been charged with sexually assaulting a woman named Andrea Constand in 2004. According to prosecutors, on the night of the assault, Cosby had urged Constand to take pills that he gave her and to drink wine. The chemicals allegedly rendered her unable to move when he committed an aggravated indecent assault against her, involving physical penetration with his fingers without her consent. Cosby has reportedly acknowledged sexual contact with the victim but claims that it was consensual.

One of the important issues in the case is whether any of Cosby’s numerous other alleged sexual assaults will be admissible in evidence against him to prove the greater likelihood that he is guilty of the sexual assault with which he has been charged in this case. Resolution of the issue will turn on how the Pennsylvania court interprets and applies its Evidence Rule 404, which, like the rules in other states, resembles Federal Rule of Evidence 404. In this column, I will explain Pennsylvania Rule 404 and then apply it to the facts of Cosby’s case.

Rule 404

Pennsylvania Rule of Evidence 404 provides that a party in litigation may not introduce evidence that a person has a propensity (“character or character trait”) for engaging in particular behavior and therefore acted in accordance with that propensity on a specified occasion. Such prohibited evidence might take the form of prior actions conforming to the propensity hypothesis or might consist of a character witness reporting his or her assessment of the relevant person’s propensity.

To make this rule more concrete, consider a hypothetical case where a criminal defendant has been charged with robbery. It turns out that this defendant has committed robbery before. Rule 404 provides that the prosecutor may not introduce the defendant’s prior robberies into evidence to show that the defendant has a propensity for committing robbery and therefore is more likely (than in the absence of such a propensity) to have committed the robbery with which he has been charged in this case. Under this rule, it would seem, Bill Cosby’s prior acts of sexual assault would be inadmissible as proof that he is inclined toward sexual assault and is therefore more likely (than he would be without such an inclination) to have committed the sexual assault for which he is charged now.

There are some exceptions to this rule. One exception provides that a criminal defendant may offer positive propensity evidence about himself to show that he is not the sort of person who would commit the crime charged. An example might involve a defendant charged with a violent crime who offers into evidence a character witness who has known the defendant for years and is prepared to testify that the defendant is a gentle person who is simply incapable of violent behavior. Interestingly, for our purposes, the Federal Rules of Evidence provide an exception for prior acts of sexual assault, offered to prove that a defendant is predisposed to commit sexual assaults and is accordingly more likely (than in the absence of this predisposition) to have committed the sexual assault with which he is charged. If this rule applied in Pennsylvania, then the evidentiary issue in Cosby’s case would be straightforward.

In Pennsylvania, however, there is no exception to the propensity rule for sexual assaults. There is, though, a caveat in Pennsylvania’s rule 404 (as in Federal Rule 404) that provides that prior bad acts of an individual may be admitted to prove something other than propensity, and the rule then gives a non-exhaustive list of examples of permissible uses, including proof of identity—for instance, that an individual has a very particular way of doing things, offered to prove that he acted on this occasion in that very particular way. If the defendant in a robbery case always sang Broadway show tunes at his prior robberies, and we are trying to determine who robbed a particular bank while singing show tunes, the defendant’s singing of show tunes in the past might be admissible to identify the defendant as the robber in this case. The Pennsylvania rule requires, however, that such evidence have probative value (relevance to the case) that outweighs its potential for unfair prejudice.

Bill Cosby stands accused not just of sexual assault but of a particular mode of committing his assaults. According to a large number of women who have come forward, Cosby in the past gave each of them pills or alcohol or both as a means of making them more vulnerable to sexual assault. The sexual assault for which he has been criminally charged also involved his allegedly urging the victim to take pills and drink wine prior to his alleged aggravated indecent assault of her. The evidence of other bad acts against other women might accordingly be admissible to prove that Cosby is more likely to have committed the crime with which he is charged than he would be in the absence of this “signature” evidence of urging targeted victims to drink and/or take pills before assaulting them.

Since different sexual assailants conduct their crimes in different ways, demonstrating a particular M.O. (modus operandi) that distinguishes this defendant could be highly probative. For this reason, the evidence of prior assaults in which Cosby reportedly gave pills or alcohol to his alleged victims might be deemed admissible against Cosby as identifying evidence. The prosecutor can say “we’re not trying to prove that Cosby is a sexual predator; we are instead introducing evidence of his particular way of engaging with intended victims that helps separate his sexual assaults from those of the crowd.” The judge may well accept this argument.

Distinguishing Identity and Propensity Inferences

One problem with this argument is that although “identity” is listed as one permissible use of prior bad acts, it is conceptually very much like the garden variety propensity inference. Instead of saying that Cosby has a propensity for sexually assaulting women, it says that he has a propensity for drugging and sexually assaulting women. Though arguably more probative on the issue than a plain vanilla history of sexual assault, admitting this evidence for the permitted inference seems to track the use of such evidence for the prohibited inference. Furthermore, unlike the case of the masked robber singing show tunes (whose identity is truly in question), the Cosby case is not a “whodunit” scenario. The relevant actors (Cosby and the accuser) are established, and the question is what the actors did or did not do. Cosby acknowledges having had sexual contact with the victim but claims that it was consensual.

Yet one might take issue with the propensity rule itself and therefore embrace the generous caveats offered within the same rule. The propensity rule, after all, asks us to ignore what many would consider highly relevant evidence on the question of guilt and innocence, namely, has the accused done this sort of thing before? Someone who has, on many occasions, been accused of committing the very crime with which he has been charged, seems much more likely to be guilty, all things being equal, than someone who has never been accused of such conduct. If one feels this way about the propensity rule, then the non-exhaustive list of caveats will provide a welcome opportunity to limit the damage of the rule by allowing more specific propensity evidence (such as “drugs women and then sexually assaults them”) to make its way into the courtroom.

One who favors the propensity rule, however, may view the caveats as unwelcome opportunities to flout a very sensible rule. Supporters of the rule say that jurors are going to have a difficult time looking at the evidence in a neutral fashion once they hear about prior misconduct, so we must protect the defendant (or whoever the propensity evidence concerns) from the jury’s likely misuse of the evidence. Another way of saying this is that whatever probative value prior bad acts might have does not outweigh their tendency to unfairly inflame the jury against the person who carried out the prior bad acts. For fans of the general propensity rule, then, the caveats should be read as narrowly as possible. And since no one is claiming that the accuser has the wrong guy, Cosby’s prior drugging and sexual misconduct should perhaps be kept out of court.

“Whodunit” Versus “What Was Done”

My view on this issue is that evidence of prior misconduct has the most relevance (for the propensity inference and for M.O. evidence) in cases like Cosby’s. In “whodunit” cases, many people not in the courtroom may have committed the same offenses in the past, and the salience of the defendant as someone who has acted in this way before is therefore unfair. The jury, in other words, is not seeing the countless individuals who have also sexually assaulted people (or, in this case, the countless individuals who have first drugged and then sexually assaulted people). In our case, however, a “what was done” situation, we know that the relevant players are Cosby and the accuser. Either the accuser is lying about what happened or Cosby really did commit the crime; there is no missing third party who might be the true culprit. As I argued in a law review article, such cases provide the most appropriate occasion for utilizing prior bad acts to prove an inclination to commit such acts. There is no risk that the police just rounded up the usual suspects and unfairly placed Cosby in the lineup.

I am ambivalent about the Cosby case. My gut tells me that the prior acts evidence at issue is extremely probative of the charged sexual assault, and my prior analysis of the subject suggests that juries will not over-count the evidence so much as count it for what it is actually worth. Nonetheless, I worry about the jury wanting to punish Cosby for his many unpunished other offenses and therefore paying less attention to the specific evidence offered about this case. On balance, because the rule does allow other uses of evidence when probative value outweighs unfair prejudicial effect, and because of how probative we all understand the evidence against Cosby to be, if I were the trial judge, I would probably admit the evidence with an instruction telling jurors that they may not punish Cosby for prior crimes and must not simply infer that “he is a sexual assailant and therefore must have committed the sexual assault charged here.” I would then trust the jury to sort out whether he in fact committed the offense with which he is currently charged.