It is crystal clear (pardon the pun) to me that Nifong is fishing for any evidence he can dig up now, because he has none that can win the case. The only caveat is that this case MUST be moved to another county, where the "privileged white boys" can get a fair trial by a jury of their peers. They currently have no peers in Durham County.
I don't know that Nifong is fishing so much with his alleged investigation as he is delaying. As long as he says he's investigating, he can delay turning over some of the evidence he has...
But what exactly can he dig up at this point? Reid and Collin seem to have good alibis. I don't know how any information on these 5 other kids ruin the 3 charged case. Further more if he is looking to indite some new people on the rape charge it will end up hurting his case on any new person and the 3 already charged. I think this is nothing more than Nifong looking to intimidate future witnesses.