Under special prosecutors Jim Coman and Mary Winstead, the state examined the evidence from scratch, interviewing key witnesses in an explosive case that combined sensitive issues of race and class.
"The result is that these cases are over and no more criminal proceedings will occur," Cooper said, calling the original prosecution a "rush to judgment" and describing Nifong as driven by "bravado."
"We have no credible evidence that an attack occurred in that house on that night," he said.
Cooper also said that he did not expect any charges to be filed against the accuser, whose account has changed multiple times in the last year. Cooper said that the accuser may be suffering mentally and may actually believe some of the stories she told prosecutors.
In addition to the dismissal decision, Cooper also proposed a law that would give the North Carolina Supreme Court the power to remove rogue prosecutors under certain circumstances.
Cooper's decision comes almost exactly one year after Seligmann and Finnerty were indicted on April 17, 2006. Evans was indicted two weeks later.
Former Duke lacrosse coach Mike Pressler, who stepped down from his post shortly after the alleged incident, celebrated the news at a press conference at Bryant University in Rhode Island, where he now serves as head coach.
"I am thrilled, overjoyed and relieved," said Pressler. "They have suffered greatly and unjustly."
The university also responded, with Duke President Richard Brodhead issuing a written statement that welcomed the news and praised the three players' families for carrying themselves with "dignity through an ordeal of deep unfairness."
The Duke campus was bitterly divided after the three players were charged, with some students coloring the lacrosse program as thuggish and others rallying around the nationally ranked athletic program.
"The attorney general did not dismiss the allegations on narrow, equivocal or legalistic ground," Brodhead wrote. "He determined our students to be innocent of the charges and said they were 'the tragic result of a rush to accuse.' In short, he used the strongest language of vindication."
Defense attorneys had released a series of documents detailing how the accuser changed key details in her story in the weeks and months after the alleged assault.
Legal analysts and forensic experts also criticized what they called a critically flawed photo identification lineup -- a lineup that led to the identification and indictment of Evans, Finnerty and Seligmann.
No DNA evidence was found matching any lacrosse players with samples from the rape kit, while DNA from unidentified men was found on the accuser's body and clothing.