I doubt there was a single case of rape allegations prosecuted without a complaining witness. Don't they have a constitutional right to confront their accuser?
In the domestic violence context, DAs sometimes go forward with cases even if a spouse refuses to go forward. They rely on other evidence. Of course, in this case there is no other evidence but Nifong is such a lunatic that may not matter. Hasn't mattered so far. FOr all we know, Precious has already decided not to go forward (like she has done every other time she has accused people of serious felonies) and Nifong is burying her until after the election.
And yes, you do have a right to confront your accuser which renders the decision to go forward moot and stupid.