RALEIGH, N.C. - On the night she accused three Duke lacrosse players of rape, a woman told a nurse she had been attacked, then told police it didn't happen before reversing herself again.

It was the first in a line of contradictions from the accuser over the next year. And with no physical evidence that an assault took place, her conflicting statements were among the most convincing evidence prosecutors cited in declaring the accused players innocent, according to a report by the state attorney general's office released Friday.

"The state's cases rested primarily on a witness whose recollection of the facts of the allegations was imprecise and contradictory," the 21-page report said, adding that the woman's changing accounts led to "insurmountable credibility issues."

Much of the information in the report was already public, but Friday's summary laid out the reasons Attorney General Roy Cooper dropped all charges in the case April 11. It also provided an emphatic final word on a criminal case that divided Durham in its early weeks.

Among the details of the report:

- When the accuser met with state prosecutors, she "changed her story on so many important issues as to give the impression that she was improvising as the interviews progressed."

- The accuser explained some contradictions in her statements by alleging photographs and other evidence had been fabricated.

- She met with prosecutors earlier this month while under the influence of prescription drugs, showing behavior consistent with witness statements from the March 2006 team party where she said the attack occurred.

When Cooper dropped charges against former players Reade Seligmann, Collin Finnerty and David Evans, he said they were victims of a "tragic rush to accuse" by Durham County District Attorney Mike Nifong, who now faces ethics charges for his handling of the case.

"We are pleased that the public will finally see the details of the exhaustive investigation performed by the attorney general's office, which proves what we have said all along and what the attorney general said on April 11th," Evans' attorneys Joseph Cheshire and Brad Bannon said Friday in a statement. "Dave, Collin and Reade are innocent and there simply was no physical or sexual assault whatsoever."

The accuser had claimed she was assaulted by three players in a bathroom during a team party at an off-campus house where she was hired to perform as a stripper. A grand jury later indicted Seligmann, Finnerty and Evans on charges of rape, kidnapping and sexual offense.

Nifong dropped rape charges in December when the accuser changed details in her story, then turned over the case to Cooper's office in January amid the ethics charges.

The report said the accuser changed key elements of her story many times, and that evidence showed Seligmann and Finnerty weren't even at the house at the time she alleged she was attacked. The report also said the photo lineups in which the accuser identified the three players as her attackers were of "questionable validity."

David Freedman, an attorney representing Nifong for his June ethics trial before the North Carolina State Bar, declined to comment because he had not read the investigation summary.