In a statement issued by Bryant -- whose trial had been days from opening arguments -- responded with an apology to the woman who had accused him.
"Although I truly believe this encounter between us was consensual, I recognize now that she did not and does not view this incident the same way I did," Bryant said. "I now understand how she feels that she did not consent to this encounter."
With the parents of the 20-year-old alleged victim looking on, District Judge Terry Ruckriegle threw out the case under a deal that means no charges will be refiled.
District Attorney Mark Hurlbert told Ruckriegle said the woman did not want to testify or otherwise participate in the trial.
"Today justice is sadly interrupted," Hurlbert said in an evening news conference.
"The prosecution wants to try this case. I want to try this case. The victim has informed us, after much of her own labored deliberations, that she does not want to proceed with this trial. For this reason and this reason only, I am dismissing this case," he said.
The woman's attorney, John Clune, said she has been through an extremely difficult time over the 14 months since she alleged she was raped and was disturbed by a series of courthouse mistakes that included release of her name and medical history.
"It is in her sincere belief that when this case ends, she does not want to be brought back into the criminal process," Clune said.
"The difficulties that this case has imposed on this woman the past year are unimaginable."
The dismissal marks a stunning turn in the high-profile case against one the NBA's brightest young stars. For months, prosecutors had insisted they had a strong enough case to win a conviction beyond a reasonable doubt.
Instead, prosecutors dropped backed away after spending thousands of dollars and just days before opening statements were scheduled to begin on Tuesday. Jury selection was scheduled to wrap up this week.
Bryant, 26, has said he had consensual sex with a then-19-year-old employee of a Vail-area resort where he stayed last summer. Had he been convicted, the Los Angeles Lakers star would have faced four years to life in prison or 20 years to life on probation, and a fine up to $750,000.
Bryant, who still faces a federal civil lawsuit filed by the accuser that seeks unspecified damages, apologized to the victim "for my behavior that night and for the consequences she has suffered in the past year."
"Although this year has been incredibly difficult for me personally, I can only imagine the pain she has had to endure," said Bryant, who also apologized to her family, his family and friends and the citizens of Eagle.
Bryant said that while the civil case remains, that part of this case "will no longer be a financial or emotional drain on the citizens of the state of Colorado."
Legal experts said a series of court rulings hurt the prosecution's case, including a decision allowing the woman's sex life in the days surrounding her encounter with Bryant to be admitted as evidence. This was expected to bolster the defense contention that she slept with someone after leaving Bryant and before she went to a hospital exam — a potentially key blow to her credibility.
The pending civil case would have also allowed defense attorneys to argue the woman had a financial motive to accuse Bryant of assault. Bryant's defense team has long argued she falsely accused him to gain the attention of a former boyfriend, and that she was given nearly $20,000 from a victims' compensation fund.
Attorneys for the accuser complained of several damaging leaks in the case, some of them accidental. The accuser's name was accidentally released by court officials at least twice.
Ruckriegle admitted mistakes had been made and took full responsibility. But he also blamed Colorado lawmakers for slashing the budgets of the state courts system, saying less staff and more work "was bound to result in mistakes."
"We had no idea these mistakes would be under such a microscope," the judge said.
Defense attorneys this week asked the judge to dismiss the assault charge, saying prosecutors had refused to turn over details that could suggest Bryant is innocent. Court rules require prosecutors and defense attorneys to exchange evidence and witness opinions before trial, a process called discovery.
In a motion made public Wednesday, defense attorneys said a forensics expert whom prosecutors had planned to call as a witness had information that "undermined the accuser's allegations and the prosecution's case, and corroborated Mr. Bryant's defense on a central issue — the cause and significance of the accuser's alleged injuries."
The filing said those opinions were not disclosed to the defense until they contacted the expert Friday.
The motion does not identify the expert, but prosecutors this spring had said they planned to call former New York City medical examiner Michael Baden to testify about the woman's injuries.
Hurlbert had said during a July 19 hearing he had decided against using Baden. He did not elaborate.
The defense motion was first reported by ABC News, which cited unidentified sources who said Baden told prosecutors the woman's injuries could have been caused by consensual sex. Baden did not return messages Wednesday.