The 19-year-old woman sat in a courtroom just a few feet from Bryant, the first time they had faced each other since their encounter last summer.
Experts said she was probably questioned about the most intimate
"The hard questions will make her quite sober as to what she's got to face and maybe put it in her mind what will happen at trial," said Southwestern University School of Law professor Robert Pugsley.
As the woman walked from a fire-exit door across a hallway into court she held her head high, eyes focused forward and appearing confident and calm, reports CBS News Correspondent Lee Frank. In the months since she met Bryant, his accuser has changed her hair color from blond to red-tinted and she has gained some weight.
Her parents entered through another door. Appearing calm and composed, she ignored a throng of reporters and photographers as she walked into the courtroom. She was finished by lunch, though it was unclear whether she will have to return for more testimony.
The next witness was Mandy Ross, a former roommate of the woman at the University of Northern Colorado. Also in the courthouse was Robert Pietrack, a high school classmate of the woman who worked as a bellhop at the resort where the alleged attack took place. He is believed to be the first person she spoke to after the incident.
Bryant, 25, faces four years to life in prison or 20 years to life on probation if convicted of felony sexual assault. The Los Angeles Lakers guard has said he had consensual sex last June with the woman at the Vail-area resort.
The defense says the woman had multiple sexual partners the week of the alleged assault and that semen from someone other than Bryant was found in her underwear during a hospital exam.
The defense says her sexual history should be admitted because it could show her injuries were caused by another sexual partner and that she had a "scheme" to have sex with Bryant and others, possibly to gain the attention of an ex-boyfriend.
"This is one of those rare cases where the defense does have a right to explore the victim's other sexual history," Loyola University Law Professor Laurie Levenson told CBS News, and the reason is because there's a key question in the case, how did she get the injuries? Did she get them because Kobe forced himself on her, or did she get those injuries from someone else?"
The prosecution fought to limit defense questioning, but was rebuffed by the Colorado Supreme Court. The hearing is the first time the woman has faced Bryant since their encounter last summer, reports CBS News Correspondent Bill Whitaker.
The judge can halt questions he believes are unfair or irrelevant and prosecutors can object.
"The whole purpose of this closed-door hearing is to determine whether this information about Bryant's accuser is relevant enough to this case to go before jurors," says CBSNews.com Legal Analyst Andrew Cohen. "But there is a decent chance that the topic of this hearing will never see the light of day at trial."
"This is a wonderful opportunity for Bryant's attorneys to cross-examine his alleged victim and to evaluate how she does on the witness stand. And that will mean a more effective cross-examination at trial. So whether the defense ultimately wins or loses this rape-shield fight it's already ahead of the game because of this free preview," says Cohen.
Former prosecutor Craig Silverman, who has been following the case, said the hearing was an "audition" for the trial during which both sides can learn about each other and about the woman's behavior as a witness.
"I imagine they (Bryant's attorneys) will be soft and easy at the start to gather as much as possible and wait until the end to become belligerent to see how she reacts," Silverman said.
Colorado's rape-shield law, like others around the country, generally bars defense attorneys from bringing up information about an alleged victim's sex life. Judges, however, can hear such testimony in private to determine whether the information is relevant and admissible as evidence.
Pugsley said defense attorneys will probably try to intimidate prosecutor Mark Hurlbert into dropping the case by showing him what they know about the woman. Hurlbert, who declined comment Wednesday, has said he is confident he has enough evidence for a conviction.
Another closed-door hearing resumes Thursday on a request by Bryant's lawyers to throw out evidence including the NBA star's recorded statements to investigators and a T-shirt stained with the accuser's blood.