Prosecutors in the office of Cyrus R. Vance Jr., the Manhattan district attorney, told the judge, Michael J. Obus of State Supreme Court, that they could not prove the case beyond a reasonable doubt because of serious credibility issues with the hotel housekeeper who had accused Mr. Strauss-Kahn of sexually assaulting her as she entered his suite to clean it.
The judge initially had issued a stay on his decision until an appellate court could hear the housekeeper’s motion to remove Mr. Vance and appoint a special prosecutor. The appeals court denied the request, concurring with Justice Obus that the argument had no legal basis.
Justice Obus’s order of dismissal brought some semblance of vindication to Mr. Strauss-Kahn, 62, after his stunning arrest more than three months ago. He was taken into custody May 14 aboard an Air France jet at Kennedy International Airport and then paraded before news cameras, disheveled and in handcuffs.
For his accuser, Nafissatou Diallo, a 33-year-old Guinean immigrant, the result caps a precipitous fall. Prosecutors initially portrayed her as a credible and powerful witness, only to say that her myriad lies about her past — which included a convincing, emotional but ultimately fraudulent account of being gang raped by soldiers in Guinea — ended up undermining the case.
Ms. Diallo, who has made her identity public, still has a civil lawsuit pending against Mr. Strauss-Kahn for unspecified monetary damages, and her lawyer, Kenneth P. Thompson, has been relentless in his assertion that Mr. Strauss-Kahn sexually assaulted his client and that Mr. Vance’s office abandoned the case too soon.
Mr. Thompson made one last desperate attempt to keep the criminal case going, filing a motion on Monday asking that Mr. Vance’s office be disqualified. But about an hour before Tuesday’s hearing started, a court clerk handed out a one-page decision in which Justice Obus denied Mr. Thompson’s motion. However, Mr. Thompson appealed, leading to Justice Obus’s suspension of his dismissal order.
The appellate division’s ruling was expected to set the stage for Mr. Strauss-Kahn’s eventual return to France, where he is a leading figure in the Socialist Party and had been considered a top candidate for the French presidency.
After the hearing, Mr. Strauss-Kahn issued a statement, characterizing the time since his arrest as “a nightmare for me and my family,” and thanking the judge, his wife and family and other supporters.
He added that he was “obviously gratified that the district attorney agreed with my lawyers that this case had to be dismissed.”
“We appreciate his professionalism and that of the people who were involved in that decision,” he continued. Mr. Strauss-Kahn added that he looked forward to “returning to our home and resuming something of a more normal life.”
The case has attracted international attention ever since the arrest; each appearance in court has drawn a carnival-like atmosphere outside, with journalists and camera crews mixing with protesters. The scene on Tuesday was no exception: Well before Mr. Strauss-Kahn arrived at 11:03 a.m., about three dozen protesters gathered, most of them in opposition to Mr. Strauss-Kahn.
To them, the case represented an instance of a powerful, wealthy man getting away with something he did to a poor immigrant woman.
But his lawyers, Benjamin Brafman and William W. Taylor III, have maintained that the sexual encounter between him and Ms. Diallo was consensual and that she was simply trying to exploit him for money.
“You can engage in inappropriate behavior perhaps,” Mr. Brafman said outside the courthouse after the hearing. “But that is much different than a crime.”
Mr. Brafman and Mr. Taylor each characterized Mr. Vance’s decision to drop the charges in such a high-profile case as “courageous.”
But Mr. Thompson, Ms. Diallo’s lawyer, said Mr. Vance not only “abandoned an innocent woman,” he also made it less enticing for other women to come forward with claims of sexual assault.
On Monday, prosecutors laid out their reasons for asking that the case be dismissed in a 25-page report that concluded that Ms. Diallo could not be believed.
“In virtually every substantive interview with prosecutors, despite entreaties to simply be truthful, she has not been truthful, on matters great and small, many pertaining to her background and some relating to the circumstances of the incident itself,” the report said.
Prosecutors said their legal and ethical obligations prevented them from going forward with a case in which they could not be certain if the accuser was telling the truth.
Ms. Diallo gave varying accounts of what she did after she said she was attacked on May 14 when she went to clean Mr. Strauss-Kahn’s suite in the Sofitel New York. In one version, she said she immediately fled to a far end of the 28th-floor hallway and remained there until she encountered a supervisor. She changed that story, the report said, saying that before reporting to a supervisor that she had been attacked, she cleaned another room on the floor, giving details of vacuuming and cleaning mirrors. In a final account, according to the report, Ms. Diallo said she had not cleaned another room after the attack, but just went to collect her supplies.
The report also cited a telephone call that Ms. Diallo made to her fiancé in an Arizona jail in which she spoke about making money off of the case, even though she previously told prosecutors that that thought had not crossed her mind.
The physical evidence in the case — including Mr. Strauss-Kahn’s semen on Ms. Diallo’s dress and his skin on her pantyhose and underwear — established that a “hurried sexual encounter” had taken place, the report said, but was not conclusive of a forcible sexual attack.
The prosecution’s original report was about three times as long, but it was scaled back to provide only the details relevant to support the legal arguments and to spare unnecessary facts that could embarrass Ms. Diallo, said a law enforcement official briefed on the case.
Some people have criticized Mr. Vance’s office for moving quickly to indict Mr. Strauss-Kahn, rather than arranging a bail package that would have allowed prosecutors more time to investigate before deciding how to proceed.
While that more deliberative course might have had the same ultimate result, it could have helped avoid the prosecution’s early pronouncements in court that the case was strong and that Ms. Diallo was credible and gave an “unwavering” account.
As it became more apparent that Mr. Vance’s office was preparing to drop the charges, Ms. Diallo took the unusual step of going public, granting interviews to Newsweek and ABC News.