NEW YORK, June 4 (Reuters) - While dozens of women have leveled sexual assault allegations at comedian Bill Cosby, destroying his reputation as "America's dad," the question of whether he will be imprisoned will hang on the words of one woman when his trial starts this week.
The outcome, taken together with the treatment of accuser Andrea Constand on the witness stand, may well affect whether women who have been sexually assaulted by powerful men seek prosecution, according to experts who study sex crimes.
"If he is acquitted, I think people will kind of shrink back, especially if the victim is treated really badly," said Aviva Orenstein, a law professor at Indiana University, who has studied sex crimes.
But Jennifer Long, a former Pennsylvania prosecutor whose non-profit AEquitas advises prosecutors on sexual violence, said she is optimistic that the sight of Constand testifying against a major celebrity could inspire more women to come forward.
Constand, a former basketball player and coach at his alma mater Temple University, has accused Cosby of drugging and sexually assaulting her 13 years ago at his home in suburban Philadelphia.
Cosby, 79, has repeatedly denied all wrongdoing in response to the accusations covering a series of alleged sexual assaults dating back to the 1960s, most of which are too old to be the subject of criminal prosecution.
The former star of the 1980s television hit "The Cosby Show" does not plan to testify during the two-week trial in Norristown, Pennsylvania, leaving Constand as the linchpin of the prosecution's case - and the main target for Cosby's attorneys during what promises to be tough cross-examination.
Cosby's lawyers have signaled they will grill Constand on why she waited nearly a year before reporting the alleged assault and why she remained in touch with Cosby for months after their encounter, even taking her mother to see one of his performances.
UNPREDICTABLE REACTIONS TO TRAUMA
Experts in sexual assault say victims often behave in inconsistent ways for a variety of reasons. For instance, it is not uncommon for victims to remain in contact with their attackers, perhaps to regain a sense of control or normalcy or to try to understand what happened, Long said.
"Although people would like to think that there's one way that victims of a crime react, we know that how victims react to a trauma is varied," she said.
Last week, Judge Steven O'Neill overruled defense objections and said prosecutors could call a psychologist to testify about how Constand's behavior is not out of place for a victim of sexual violence. Such experts were not permitted until 2012 in Pennsylvania, which was the last U.S. state to allow such testimony.
Constand's testimony will be buttressed by that of another accuser, who says Cosby drugged and assaulted her in a strikingly similar attack in 1996.
That woman, known only as Kacey, could help sway jurors who harbor doubts about Constand's story, legal experts said. Studies show that jurors who learn of prior incidents are far more likely to convict a defendant, according to Orenstein, who has researched the use of so-called prior bad acts witnesses in sexual assault cases.
"There's a general consensus that knowledge of priors totally jacks up the conviction rate," she said.
The judge is allowing Kacey to testify only to show a pattern of behavior by Cosby or to undercut any defense claims that he may not have understood Constand was unable to consent; jurors are not allowed to consider what Kacey's story says about Cosby's character.
But that legal distinction can be a difficult one for jurors to follow, said David Harris, a law professor at the University of Pittsburgh who has followed the case.
"What you have is the jury drifting from its real job," he said. "The case in court today is: Did Bill Cosby assault Andrea Constand? The jury could say, 'Well, I'm not sure about that, but he's kind of a bad guy.'" (Reporting by Joseph Ax; editing by Scott Malone, G Crosse)