With every new court filing, attorneys for three Duke University lacrosse players appear to open a new front in their relentless assault on the prosecution, challenging District Attorney Mike Nifong to defend his decision to charge their clients with rape.

While Nifong has yet to respond — either in public statements or formally in court — there is no indication the defense motions have dented his resolve to bring the case to trial.

"If he is convinced of the truth of the charges, he has every right to pursue it, even if it's an uphill battle," said Steve Cron, a criminal defense attorney of 32 years who practices in Santa Monica, Calif., and has represented several celebrity defendants.

"If he is convinced that the charges aren't meritorious, it's his constitutional obligation to dismiss the charges regardless of what pressure he gets from local police or media or the population. That's irrelevant to his decision. It is simply about seeking justice and that's his obligation to pursue it."

As he has for weeks, Nifong declined to comment about the case Friday, the day after defense attorneys for one of the three charged players said in a motion the second woman hired to strip at the March 13 team party initially told police the accuser's allegations of rape were a "crock."

Instead of speaking out, Nifong has encouraged the public to come to trial to hear his evidence.

"The prosecutor should not try his case on the front page of the paper," said Norm Early, a former district attorney in Denver who now works with the National District Attorneys Association. "This case will come out in court when the evidence is heard, and the fact that members of the public and media continue to clamor to reveal more of his case should not make him do so."

The accuser told police she was dragged into a bathroom and raped, beaten and choked for about 30 minutes during the party. The allegations led a grand jury to indict Dave Evans, 23, of Bethesda, Md.; Collin Finnerty, 19, of Garden City, N.Y.; and Reade Seligmann, 20, of Essex Fells, N.J., on charges of rape, sexual offense and kidnapping.

Defense attorneys insist all three are innocent, and the men are free on $400,000 bail each. A trial isn't expected to begin before spring 2007, and the next court hearing is scheduled for June 22.

In filings Thursday, the defense also attacked the validity of the medical exam performed on the accuser, which Nifong has said led him to believe a crime occurred at the party. The medical records included in the defense motion indicate the exam found only a small scratch on the accuser's knee, a cut on her heel and vaginal swelling.

An attack on that exam and other possible prosecution evidence is a common defense tactic, Early said.

"The defense attorneys are there to muddy the waters," Early said. "You can't expect anything they say to be said without viewing it through their own prism. They're there to obfuscate the facts. They're not there to educate the public."

The flow of paper from the defense continued Friday, as Finnerty's attorneys filed three discovery motions seeking reports from two police officers who were with the accuser in the hours following the party before she arrived at an area hospital.

They also sought original notes and documents from investigators, and more detailed reports on all photo lineups they conducted.

The last motion suggested that police may have conducted six or more photo lineups, in which the accuser was shown photos of Duke lacrosse players and asked if she could identify her attackers.

Evans' attorney, Joseph Cheshire, filed a motion last month saying the woman failed to identify at least one of the three charged players in a photo array eight days after the reported attack, then selected him as an attacker more than two weeks later.

Defense attorneys also have said DNA testing failed to conclusively link any player to the accuser, and that material recovered from the woman matched a single male source who was not a member of the team.