DENVER -- When Kobe Bryant said he "made the mistake of adultery," he handed prosecutors the challenge of proving that whatever happened between him and the woman who accused him of sexual assault was against her will.

"How do they prove it's not consensual? That's the whole enchilada right there," said Steve Kron, a longtime sports criminal defense attorney in Los Angeles.

"It's hard to prove (with) two adults in a room having sex that the sex was not consensual," he said.

Bryant, the Los Angeles Lakers superstar, was charged Friday with felony sexual assault against a 19-year-old woman who worked at an exclusive spa where Bryant was staying while in Colorado for knee surgery.

"I am innocent of the charges filed today. I did not assault the woman who is accusing me. I made the mistake of adultery," Bryant said in a written statement.

Bryant reiterated his innocence later at a news conference at the Staples Center in Los Angeles. His lawyer plans to plead not guilty.

Prosecutors said the alleged victim would not be made available for comment. A man at her home said there would be no statement.

"Now it's going to be interesting," said Kron, who has represented Paula Poundstone and other celebrities.

"Do you have witnesses or physical evidence? Was she bruised, scratched, injured in some fashion?" Kron said.

Kron and others said Bryant's attorneys will scrutinize the woman's life and look for ways to discredit her. Jurors may not want to believe allegations against a superstar, they said.

"As a celebrity, he comes in with a super presumption of innocence," said Loyola University Law School Professor Laurie Levenson in Los Angeles. "Any defendant whom the public knows by his first name, their reaction is, 'No, not Kobe."'

But she said attitudes may be different in Colorado than in Los Angeles.

"In this small town in Colorado, they may care more about the victim," she said.

Kron said financial questions may also be raised.

"Are there financial incentives for her? We all know what Kobe's worth," he said.

The reaction of Bryant's wife, Vanessa, will be crucial to both jurors and the public, said Robert Pugsley, a professor of criminal law at Southwestern University School of Law in Los Angeles.

"It will give the public a sense that he acknowledged that something did occur but it also says it's a moral lapse and not a criminal act," he said.

Vanessa Bryant issued a statement Friday saying her husband "has made a mistake -- the mistake of adultery."

But she added, "I know that he did not commit a crime, he did not assault anyone. He is a loving and kind husband and father. I believe in his innocence."