Steubenville Rape Trial: Prosecutor Says Accuser Too Drunk to Consent

March 13, 2013 — -- Prosecutors in a closely watched trial beginning today in Steubenville, Ohio, opened their case against two high school football players by describing a night of partying went awry when the teens allegedly sexually assaulted a girl who was "stumbling, her speech was beginning to slur, losing her balance."

As the alleged victim, a 16-year-old from West Virginia, was driven from party to party Aug. 11 after becoming intoxicated and "substantially impaired," the boys took more and more liberties with her, prosecutor Marianne Hemmeter said today in court.

"This case will hinge on not only the defendants' knowledge of her substantial impairment but their exploitation of that knowledge when they treated her like a toy on Aug. 12, 2012," she added.

RELATED: Steubenville Scandal in Photos

One teen, defendant Ma'lik Richmond, 16, is accused of raping the girl by penetrating her vaginally with his finger. The other boy, Trenton Mays, 17, is also charged with rape for using his hands to vaginally penetrate her as well, and distributing child pornography for texting images of the girl.

For more on this story, watch "20/20" Friday, March 22 at 10 ET

Hemmeter further accused Mays of trying to engage in oral sex, but was unable to and instead allegedly masturbated on her while at the home of another student in nearby Wintersville, Ohio.

At one point in the night, Hemmeter said, some teenagers talked about paying money to urinate on the victim, and watched as she vomited in the street with her top removed. There is no evidence that anyone urinated in the accuser.

Hemmeter said that aside from the victim, only Mays' DNA was found on a blanket at the scene.

RELATED: Steubenville Script Goes Awry for Accused Teen

The "degradation continued," Hemmeter said, when two photos of the victim circulated on social media, first through the school and then across the internet. One photo shows two people carrying the victim, who appears to be unconscious, by her hands and feet.

Another photo shows the victim "asleep on her side with what appears to be semen on her stomach," Hemmeter said.

At least one of the photos was initially sent from Mays' cellphone, leading to the additional child-pornography charge against him.

The boys are on house arrest, attending school at a juvenile-detention facility. They are being tried in a juvenile court and if found guilty could serve time until they turn 21.

Both boys have denied the charges. Richmond's lawyer declined to make an opening statement.

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But he has told ABC News' "20/20" that what occurred that night was consensual.

Brian Duncan, a lawyer representing Mays, said simply: "Trent Mays did not rape the young lady in question."

In an exclusive interview recently with "20/20" anchor Elizabeth Vargas, Richmond said, "I didn't rape anybody. I didn't witness a rape going on.

"And if I would have thought that somebody was being raped or anything like that, I would have stopped it."

The case drew international attention after photos of the young woman spread via social media and questions were raised about why more students, who witnessed the alleged assault were not charged.

The case drew further attention when some outside the small rustbelt town accused local officials of willfully protecting the football players, seen as hometown heroes.

For more on this story, watch "20/20" Friday, March 22 at 10 ET