DURHAM, N.C. (AP) – Standing before a mostly black audience, the district attorney in charge of the Duke University rape investigation said Tuesday he does not need DNA to bring charges and vowed, “This case is not going away.”

District Attorney Mike Nifong spoke one day after defense attorneys said DNA testing failed to connect any of Duke’s lacrosse players to the alleged attack on a black stripper who said she was raped at a party by members of the nearly all-white 47-man team.

Nifong stopped short of confirming the defense assessment of the DNA results, but said the case would not be hampered by a lack of DNA evidence.

“It doesn’t mean nothing happened,” Nifong said at a public forum at North Carolina Central University, where the 27-year-old alleged victim is a student.

“It just means nothing was left behind.”

No charges have been filed.

Nifong said prosecutors were awaiting a second set of DNA results, but did not say how those differed from the tests reported Monday.

Nifong added that in 75 percent to 80 percent of sexual assaults, there is no DNA evidence to analyze.

The district attorney said a rape case can built on testimony from the alleged victim and other witnesses.

Nifong also said the hospital exam of the woman has led him to believe a crime occurred at the March 13 party.

According to court documents, a doctor and a specially trained nurse found the alleged victim had “signs, symptoms and injuries consistent with being raped and sexually assaulted.”

“My presence here means this case is not going away,” Nifong said to applause from an audience of about 700.

The allegations have led to days of protests on and off the Duke campus and heightened racial tensions around Durham.

Some students at North Carolina Central, a historically black university a few miles away, assailed Nifong for his handling of the case and the media for its portrayal of the alleged victim.

“You all know if this happened at Central and the young lady was from another school or another ‘persuasion,’ the outcome would have been different,” said Toloupe Omokaiye, suggesting to applause from the crowd that the alleged attackers would have been jailed already.

Nifong said that he has never engaged in racial favoritism and that arresting suspects too quickly could harm the case.

“I have been criticized by both sides in this case,” he said.

“There have been people who have said that I should have given up this case a long time ago, and there are people who have said I should have already indicted, moved against somebody with some charges. The fact is that this case is proceeding the way a case should proceed.”

Nifong later told a questioner, who asserted the victim had positively identified her three attackers, that her information was incorrect.

The district attorney faces two challengers in a May 2 primary election.

Asked by a member of the audience about the campaign, he said, “As the district attorney, you do not get to choose what crimes occur and when they occur. This is not about an election. This is about justice.”

Nifong refused to take any questions from reporters after the forum.

Bill Thomas, a defense attorney for one of the team captains, urged the accuser to recant, saying he believes she made up the allegations to avoid a charge of public drunkenness.

“It is my sincere hope that she comes forward and tells the truth in this matter and allows these young men to go on with their lives and for this community to heal,” Thomas said.