Andrea Constand
"He has no choice at all but to go to trial or plead guilty," one analyst said.
The first criminal charge against Cosby can now move forward.
The comedian's defense said there was an oral agreement that he wouldn't be prosecuted.
Bruce Castor will be a key witness for the defense at a Feb. 2 hearing over what Cosby's lawyers have called a "non-prosecution agreement."
WHAT'S HAPPENING
His accuser says she was drugged so that she couldn't move or speak while Cosby assaulted her.
More than 50 women have accused Cosby of sexual assault or unwanted advances, but these are the first criminal charges filed against him.
The statute of limitations runs out in January, so the clock is ticking.
