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A teenager who was granted immunity from prosecution has testified he saw a friend perform a sexual act on a 16-year-old girl after a party in eastern Ohio last summer.

The judge granted the 17-year-old immunity Friday in Jefferson County juvenile court before he testified at the trial of two high school football players charged with raping the West Virginia girl.

Testimony from three teenage boys who watched the alleged attacks is a crucial part of the state's evidence because the girl says she doesn't remember what happened.

The witness testified that he recorded part of the encounter but later deleted the video because he realized he'd done "something stupid and wrong."

Friday's testimony followed evidence introduced Thursday in the form of sometimes graphic text messages in which one of the defendants gave differing accounts of what happened between him and the girl. At one point the defendant appeared to enlist the help of a friend in whose basement one of the alleged attacks happened to cover up the event.

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    In other messages introduced by the prosecution, the girl begged a friend for information about the night, saying she had no memory of the evening and feared she might have been drugged.

    "Swear to God I don't remember doing anything with them," the girl wrote to the friend who authorities say saw the assaults.

    "I wasn't being a slut. They were taking advantage of me," she also wrote to the same boy.

    The defendants, ages 17 and 16,  are charged with digitally penetrating the West Virginia girl, first in the back seat of a moving car after a party Aug. 11 and then in the basement of a house. The 17-year-old also is charged with illegal use of a minor in nudity-oriented material. The two maintain their innocence.

    Prosecutors insist the girl was too drunk to consent to sex, while defense attorneys have portrayed her as someone who was intoxicated but still in control of her actions. Witnesses have said she was so drunk she threw up and had trouble walking and speaking.

    In one text after the alleged assault, the girl told a boy who prosecutors say watched the attack, "Wait, I think I was drugged. I know I have no memory from after I left," the party.

    Special Judge Thomas Lipps is hearing the case without a jury. He told participants Thursday he would keep the trial in session well into the evening and through the weekend.

    The case has riveted the small city of Steubenville amid allegations that more students should have been charged and led to questions about the influence of the local football team, a source of a pride in a community that suffered massive job losses with the collapse of the steel industry.
    A police captain testified Thursday about finding two photos of a naked girl on a cell phone belonging to the 17-year-old.

    The texts introduced Thursday in juvenile court also included ones in which the 17-year-old defendant admitted that he digitally penetrated the girl. In other messages, he told friends he'd participated in a different, mutual sex act with the girl.

    He also sent messages to his friends to try to get them to gloss over what happened that night. In a text to a boy who lives in the house where the second attack is said to have happened, he wrote, "Just say she came to your house and passed out."

    In another message that prosecutors said the defendant sent to the girl's father, he said, "this is all a big misunderstanding."

    Prosecutors also presented texts sent by the 17-year-old to friends in which he suggested Steubenville football coach Reno Saccoccia would let the players involved off lightly.

    The coach "...took care of it," he said in one text introduced by prosecutors.

    "Like he was joking about it so I'm not worried," he said in another text.

    Saccoccia has not commented about the allegations, and Steubenville school officials have refused to make him available. Phone and email messages were left after hours for Superintendent Michael McVey. The district has promised to boost education programs about bullying, date rape and sexual harassment and add training for faculty and staff members.

    Additional testimony Thursday came from a former Steubenville high school student who said he considered the girl his friend and said she was extremely drunk the night of the party. He said he was upset after hearing about the alleged assault and texted the 17-year-old defendant.

    Dissatisfied with his account, he texted back: "I saw the pix, bro. Don't lie."

    Walter Madison, an attorney for Richmond, challenged the former student’s account, saying he may have exaggerated in his mind the girl's intoxication because of his anger over the allegations.

    Authorities said they collected 17 cellphones in their investigation. The evidence they yielded is considered crucial to prosecutors' case against the boys because of photos taken that evening.

    If convicted, the defendants could be held in a juvenile jail until they turn 21.

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    The Associated Press contributed to this report.

    Editors’ Note: The Associated Press named the minors charged due to the fact they have been identified in other news coverage and their names were used in open court. FoxNews.com will not name the defendants.