Editor's note: This report contains graphic language throughout.
Harrisburg, Pennsylvania (CNN) -- A Pennsylvania judge ruled Friday that the perjury case against two former Penn State university officials will go to trial over their roles in a child sex abuse scandal involving former assistant football coach Jerry Sandusky.
Tim Curley, Penn State's former athletic director, and Gary Schultz, a university vice president who oversaw campus police, have been charged with perjury and failing to report an alleged 2002 sexual assault of a child.
The decision followed Friday's testimony of prosecutors' star witness in the case against Sandusky, who faces more than 50 counts involving sexual acts with 10 boys since 1994.
Mike McQueary testified that he told university officials that he saw Sandusky possibly sodomizing a boy in 2002, saying that what he saw was "extremely sexual in nature."
But during a court reading of Curley's earlier testimony, the former athletic director said he was not made aware of any sexual activity.
Curley, who after the alleged incident restricted Sandusky from using university property, said his decision was based on what was considered inappropriate but not sexual conduct.
He said he thought McQueary was just "uncomfortable with (Sandusky's) behavior and didn't think it was appropriate for Jerry to be in the showers with a young person."
But McQueary said, "There's no question in my mind that I conveyed to (university officials) that I saw Jerry with a boy in the shower and that it was severe sexual acts going on and that it was wrong and over the line."
Curley's attorney, Caroline Roberto, said after Friday's decision that McQueary continues to face credibility issues, while Schultz's attorney, Thomas Farrell, questioned why police were never alerted.
Sandusky, meanwhile, has pleaded not guilty to all charges while denying any sexual activity with his accusers. Regarding the 2002 incident in the showers, he has said that he and the boy were just "horsing around."
McQueary, a former Penn State quarterback, testified that he met with Curley and Schultz to inform them about the alleged incident about nine days after first alerting head coach Joe Paterno.
In a graphic description of the alleged events, McQueary testified that he walked into a locker room and heard someone in the shower.
He said he heard rhythmic slapping sounds, like that of skin on skin.
"I looked in the mirror and shockingly and surprisingly saw Jerry with a boy in the shower," McQueary told the court.
He said Sandusky was behind the boy, and the boy was up against a wall. He said he believes Sandusky was sexually molesting the boy, but he did not see insertion and did not hear protests. He said he believes the two were engaged in intercourse, but he could not be sure.
"They were as close as they could be," he added.
McQueary then said he looked away for a few moments, and when he took a closer look, the two were standing apart.
"They had turned so their bodies were both facing me. ... They looked directly in my eyes," he said. "Seeing that they were separated, I thought it was best that I leave the locker room."
He added that he felt "shocked" and "horrified" afterward.
"I was not thinking straight," he said, adding that he was "sure (the incident) was over" when he left.
But McQueary acknowledged he doesn't know what happened after leaving. He also testified that he never tried to find the boy.
McQueary, then a graduate assistant, said he called Paterno -- who was fired in the wake of the scandal -- the morning after, telling him that he "saw Jerry with a young boy in the shower, and it was extremely sexual in nature, and I thought I needed to tell him about it."
McQueary testified that the former head coach was "shocked" and "saddened" on hearing the allegation.
"He said, 'I need to think and tell some people about it.' "
But McQueary didn't meet with university officials to explain what he saw until more than a week after first informing Paterno, he testified.
As far as McQueary knew, Paterno also never tried to find the boy, McQueary said. He added that he couldn't be certain whether he ever used the word "intercourse" when describing the alleged incident to university officials.
He further testified that he did not alert police, saying that he instead told Curley and Schultz.
"In my mind, that is the police," McQueary said. "I want to make that clear."
When pressed about why he went to university officials and not police, McQueary said it was "because it was delicate in nature, and I tried to use my best judgment."
Sandusky, who was Penn State's defensive coordinator when he retired in 1998, met his accusers through a youth charity he founded, the Second Mile. According to prosecutors, he would hug, tickle and wrestle with the boys before allegedly crossing the line and sexually abusing them.
In November, the summary of a grand jury report was released, contending that Sandusky sexually abused the boys in the basement of his home, hotel rooms, a high school wrestling room and -- based on McQueary's account -- the locker room for Penn State's football team.
Sandusky waived his right to a preliminary hearing Tuesday in Centre County, a two-hour drive from Harrisburg. From the courthouse's steps, his attorney, Joseph Amendola, took shots at McQueary's credibility during a long talk with reporters.
He suggested that had McQueary told Paterno, Curley and Schultz that he had seen Sandusky raping a boy in the showers, they would have done more than order him to stop bringing Second Mile children on campus.
"If we destroy McQueary's credibility, then we put the credibility of all others involved into question," Amendola said.
In its report, the grand jury found that McQueary was a credible witness after hearing all the testimony.
According to the grand jury report, McQueary testified that, as he walked into the locker room, he saw the lights were on and heard the showers running.
As he put his sneakers into his locker, McQueary looked into the shower and saw a naked boy, about 10, "with his hands up against the wall being subjected to anal sex by a naked Sandusky," the report said.
McQueary, an assistant football coach placed on administrative leave this fall amid the scandal, told the grand jury he was shocked, then noticed that Sandusky and the boy saw him. He left the building "distraught," according to the grand jury's report.
McQueary first reported what he saw to his father and told Paterno what he had seen the next day. The head coach himself testified to a grand jury that McQueary told him he saw Sandusky "fondling or doing something of a sexual nature."
His father, John McQueary, testified Friday that he followed up with Schultz, who "knew about it and something was being done."
Asked whether McQueary reported seeing an act of sodomy, Curley responded, "Absolutely not," the grand jury reported.
Schultz testified that he recalled being told at a meeting that Sandusky "may have grabbed the boy's genitals while wrestling" and agreed it would be inappropriate sexual conduct between a man and a boy, the grand jury said. But he also testified that the allegations made were "not that serious" and that he and Curley "had no indication that a crime had occurred."
Neither man reported what he'd been told to local or campus police.
"The grand jury found that portions of the testimony provided by Curley and Schultz were not credible," the report said.
Curley, 57, is now on leave, and Schultz, 62, retired in the wake of the allegations. Days later, Penn State trustees ousted President Graham Spanier and Paterno amid criticism that they could and should have done more.
Prosecutors were out in force for Friday's hearing before Judge William Wenner. According to the state attorney general's office, Chief of Staff Bruce R. Beemer will lead the prosecution along with Frank Fina and E. Marc Costanzo, deputy attorneys general.
CNN's Susan Candiotti and Ann O'Neill contributed to this report.