have to agree with the others....and yes, I have been in a situation where I was assaulted, did call the police, etc. But it was a stranger and they never found him, so there was never a prosecution there either. For 28+years, I've dealt with it and gotten help/counseling and live a pretty normal life. If your wife is still experiencing issues, I highly suggest she get therapy/help/counseling. She may think a prosecution now will do something for her, but I can almost guarantee it won't. And as other said, it is going to be virtually impossible to prove especially if she told no one at the time. And even then it would be tough this much later.
What Mr Cosby had against him were multiple allegations over a long time period (if I understand it correctly) and that possibility that he drugged them unbeknownst to them, not that they had made a bad choice of downing shots.
I truly feel for your wife that she has carried this for so many years. At some point though it is in her best interests to deal with it through therapy/counseling rather than the courts at this juncture.

