This rule could determine Cosby's fate

Story highlights

  • Danny Cevallos: Pretrial motions, not trial itself, may set Bill Cosby's legal destiny
  • Outcome could depend on Rule 404b, which governs evidence of past bad behavior

Danny Cevallos is a CNN legal analyst and a personal injury and criminal defense attorney practicing in Pennsylvania and the U.S. Virgin Islands. Follow him on Twitter @CevallosLaw. The opinions expressed in this commentary are solely his.

(CNN)Of the more than 50 women who have come forward accusing Bill Cosby, only one case, that of Andrea Constand, has resulted in criminal charges. And on Tuesday, a judge ordered that the case, three counts of aggravated indecent assault, can proceed to trial against Cosby, most likely sometime in the next year.

Danny Cevallos
Cosby's attorney offered a preview of what to expect at trial: The defense will meet prosecution witnesses head on and confront them with every flaw in their testimony. Still, the most important battle for the defense may not be the trial -- it will come during pretrial motions.
    That crucial issue to be decided: Will other accusers be allowed to testify against Cosby in addition to Constand?
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    This question is critical, because after the preliminary hearing Tuesday, it is clear that Constand's testimony will not be the strongest evidence against Cosby at trial. The hearing was an overview of her prior unclear statements, foggy memory and curious behavior with respect to Cosby before and after the alleged crimes.
    The defense will surely develop these elements more fully at trial. Indeed, Cosby's attorney effectively cross-examined police detectives whose tasks involved little more than reading Constand's statements into the record. Nothing the court heard Tuesday bodes well for the actual complainant when she ultimately takes the stand.
    I'm not going out on a limb to say that this is not one of the commonwealth of Pennsylvania's stronger cases. Remember, a prior district attorney investigated this case and concluded that the evidence was not enough to secure a conviction and declined to prosecute. The case then languished for a decade and was resurrected just before the statute of limitations expired.
    Like plumbing and sushi, criminal cases do not get better with age -- they only weaken. Witnesses vanish and memories fade.
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    So then, the prosecution may have to win this case by proving that Cosby committed aggravated indecent assault by using incapacitating drugs or acting while the victim was unconscious. Except ... the kicker is that the evidence might involve completely different incidents, with completely different women, at completely different times.
    You may be asking: Wait, what? How can the prosecution do that? What happened to putting a person on trial for only that with which he has been charged?
    Rule 404(b) of the Pennsylvania Rules of Evidence happened.
    It's a rule used strategically by prosecutors all over the country to introduce this kind of evidence against defendants. This is why the pretrial motion stage -- where the judge decides which of these "other acts" witnesses may testify -- may well determine the outcome of the whole case.
    As strange as this sounds, in fairness, this admittedly biased member of the defense bar concedes that evidence of other bad things a person did in the past could be an indicator of one's character traits, which in turn might be indicative of his present guilt. Still, because of the risk for abuse by prosecutors, evidence of prior bad acts may not be admitted into evidence solely to establish bad character or criminal propensity.
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    But the exception known to many as Rule 404(b) permits that same forbidden evidence of prior wrongs -- so long as it is used for "other purposes." For example, if the evidence tends to prove a common scheme, or discounts the possibility of simple mistakes, or where there is some logical connection between yesterday's acts and today's alleged crime -- that evidence may be admitted. As a final safeguard for the defendant, the prior acts must satisfy a balancing test: The bearing on the case must outweigh the prejudice to the defendant.
    In the Cosby case, the prosecution will file pretrial motions to allow as many accusers as possible to testify under Rule 404(b). Prosecutors will argue that the other accusers' stories of being drugged and having sex are so similar that it shows Cosby's modus operandi and should be admissible.
    The defense will counter that these unproven, uncharged other acts are not similar, not relevant, and, even if they were, they are too prejudicial to meet the balancing test. Particularly, those acts that were remote in time should not be admitted, because they are of particularly dubious value.
    For those prior acts that are admitted, the court gives a cautionary instruction to jurors, most likely in confusing legal jargon, that they may only consider other women's stories as evidence of a "common scheme or plan" -- not as evidence of the defendant's actual guilt.
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    Assuming that instruction is even understood by the jury, is it realistic to think these instructions can un-ring the prejudicial bell of evidence of other women's experiences of alleged assault at Cosby's hands?
    Ultimately, even though the law favors the defense by discouraging admission of prior bad behavior, prosecutors know the numbers favor them in the long run in this case. If, for instance, the prosecution seeks to admit 50 accusers and is only successful with five of them, then it has lost the percentages battle but possibly won the war. The prosecutors know they don't need 50 accusers to testify -- even two or three women testifying about prior similar behavior would be devastating to Cosby.
    The rules ostensibly protect defendants from this evidence, but it sure doesn't feel like that to defense attorneys. It feels like a pile-on when prosecutors charge your client with one crime, then seek to dump an additional box of bad prior conduct in your lap for your client to defend.
    Cosby's attorneys may be successful keeping out almost every other accuser, but the odds are that one might slip through. And that one might be enough to convict a defendant, even in a case such as this one, where the complainant has credibility problems.
    This case raises an important question about the policy underlying Rule 404(b): if the prosecution's case is weak, maybe we should reconsider a rule that allows prosecutors to prove their case with allegations that don't concern the charged crime.