Bill Cosby's Propensities

By Sherry Colb

In my column for this week, I discuss the rule against character evidence and how it might be applied to Bill Cosby's case.  The rule in question, Rule 404 (under Pennsylvania state law), provides that evidence of a person's character may not be introduced in evidence to show that the person acted on a particular occasion in a manner that corresponded with that character.  An example would be in a murder trial, one could not offer evidence that the defendant had committed several murders in the past, as tending to make it more likely that he committed the one of which he now stands accused.  The character rule has a caveat, however, that permits the introduction of prior bad acts evidence if offered to show something other than character (and in a criminal case, the probative value outweighs any unfair prejudice).  A non-exhaustive list of examples includes proving identity or absence of mistake.

As I explain in the column, fans of the general rule would tend to want to limit application of the caveats and would accordingly wish to exclude evidence of Cosby's behavior in prior sexual assault situations (i.e., giving women pills and drinks and then assaulting them in their vulnerable state).  I conclude, with some ambivalence, that the evidence of Cosby's prior conduct ought to be admitted against him to prove an M.O. (modus operandi) by which he engages with women he intends to assault.

In this post, I want to talk about an oddity in the rule against character evidence. One of the exceptions to the rule applies to witnesses. That is, it is permissible to introduce evidence of a witness's character (including prior convictions) to show that the witness is characteroloigcally a liar and is therefore more likely to have lied on a particular occasion (such as when he took the stand and said that he is innocent). This is strange for a number of reasons highlighted years ago by the late Professor Richard Uviller. These are Uviller's insights, but I find them so compelling that I thought it worthwhile to share them in this blog post.

Consider first the fact that when someone is accused of a crime, one of the most helpful sorts of evidence we might want to see--to determine guilt or innocence--is what sort of history this person has.  Has he done this thing he stands accused of doing before, or is this the first time, according to the allegations?  This inference, however, is impermissible because we worry that juries will overvalue evidence of past misconduct and have a hard time neutrally assessing guilt in this case. What juries may consider, though, is prior convictions as evidence that he is a liar and is therefore lying when he takes the stand and says he is innocent.  As a result, a criminal defendant with prior convictions (even for crimes having little bearing on sincerity) will be highly motivated to stay off the witness stand and thereby ensure that such prior convictions stay out.

What Uviller points out is that people tend not to have a clear character for telling the truth or for lying.  Furthermore, and more importantly, the motivation for a criminal defendant is to say "I am innocent" regardless of whether he is guilty or innocent and regardless of whether he is a liar or a truth-teller.  That motivation (to exonerate himself) overwhelms the role of any character he has for telling the truth or lying.  As a result, a defendant on the witness stand -- even if he is a known liar -- will tell the truth and say he is innocent if he is in fact innocent.  And a known truth-teller, who just about never lies, will say he is innocent even if he is in fact guilty. The incentives simply line up that way, so it is not informative to learn that the criminal defendant witness is a liar (unless, of course, he is charged with committing perjury), and most prior crimes will say more about his criminal propensities than his lying propensities.

I proposed once that we could solve a piece of this problem by prohibiting testimony by criminal defendants in their own cases. Once prohibited, no one would take the defendant's silence as evidence of guilt (and though the judge currently tells the jury not to count silence against the defendant, this is a very difficult instruction to follow), and the jury would not be asked to consider prior convictions as proof of veracity (of which they are slim proof indeed). There is something seemingly outrageous about keeping criminal defendants off the witness stand, but at the moment we really are keeping many off the stand anyway by threatening the introduction of prior convictions if they testify. Perhaps having to testify in one's own defense is more of a burden than a privilege, given the admissibility of prior convictions. Under our existing approach, only defendants with no prior convictions can confidently take the witness stand and tell the truth or lie, as their motive to say "I'm innocent" tells them.

Juries are far savvier, I think, than we give them credit for.  I once asked a friend who was on jury duty whether the defendant testified in the case on which she had sat. She said no. I asked her why she thought he didn't testify, and she said that she and the other jurors just assumed that he had a prior record. Neither she nor the others on her panel were attorneys, to my knowledge. So if she and others knew why the defendant didn't testify, then it is likely the case that other juries do too.

So what does any of this have to do with Bill Cosby? Well, he does not have prior convictions (that I know of) and certainly not priors for sexual assault. On the other hand, he has a large number of women who say that they were sexually assaulted by him. As I explain in my column, their testimony cannot be admitted for the proposition that "he has sexually assaulted before, so he's more likely to have sexually assaulted in this case," though this would be permissible in a federal trial (under Federal Rules 413-415).  For Bill Cosby, the question is whether his reported tendency to intoxicate his victims before sexually assaulting them fits within the caveat that Pennsylvania Rule 404 offers (for using prior bad acts to show something other than character). I suggest in my column that it does. If it does not, however, I will be curious to know something about the people selected for his jury who have no idea that many women have accused Cosby of sexual assault, who also know nothing about the alcohol and pills he allegedly used to make them more vulnerable. Perhaps the application of Pennsylvania Rule 404 in this case is largely moot because of what the jury pool almost certainly already knows.