Do you think Nifong would have gone to such lengths if he believed the students were guilty? He's going to such lengths precisely because he knows they're innocent; if they were guilty, such lengths wouldn't be necessary.
I don't even think he considered guilt or innocence. I think he saw his opportunity to pander to the voters and took it. I think he's too stupid to realize the ramifications of his course of action. Allegedly, he never even interviewed the accuser. How can you weigh the credibility of the allegations if you don't interview the victim? We did it every time!