(CNN) -- Pittsburgh Steelers quarterback Ben Roethlisberger will not face criminal charges after he was accused of sexually assaulting a woman at a nightspot, a Georgia prosecutor said.
Roethlisberger was accused of attacking a 20-year-old woman in the bathroom of a Milledgeville, Georgia, bar and restaurant called Capital City.
"The sexual allegation against Mr. Roethlisberger cannot be proven beyond a reasonable doubt," Ocmulgee Judicial Circuit District Attorney Fred Bright said. "Therefore, there will be no arrest made, nor criminal prosecution of Mr. Roethlisberger for his actions here on March 5, 2010."
Police talked to Roethlisberger, 28, and the woman at the scene immediately after the incident was reported at the nightclub. The woman alleged that Roethlisberger was the perpetrator.
The woman, however, also made it clear that she did not want to pursue charges, Bright said. Her desire did not influence his decision not to prosecute, Bright said.
The woman was part of a group mingling at the club with Roethlisberger's friends, authorities said. The groups had been bar-hopping separately earlier in the evening, authorities said.
Roethlisberger followed the woman into a bathroom at the club, and "significant questions about what occurred persist," Bright said, reiterating that he did not have enough evidence to prosecute successfully.
The doctor who examined the woman told investigators that he could not tell whether bruising on her genitals was from sexual assault, Bright said.
A rape-evidence kit found a small amount of male DNA but not enough to create a profile, he said.
Bright said that if there had been enough evidence to prosecute, he would have.
"We are not condoning Mr. Roethlisberger's actions that night, but we do not prosecute morals," he said. "We prosecute crimes."
Roethlisberger has guided the Steelers to two Super Bowl championships.
Last year, a civil complaint filed against Roethlisberger also alleged sexual assault. He denied the allegation made by an executive casino host at Harrah's Lake Tahoe in Nevada, saying, "Her false and vicious accusations are an attack on my family and on me; I would never, ever force myself on a woman."
Roethlisberger and eight Harrah's employees are named in the suit, which seeks at least $390,000, plus unspecified punitive damages, from the defendants.