Updated 3:54 p.m. ET
HARRISBURG, Pa. - A Penn State assistant football coach testified Friday that he believes he saw former assistant coach Jerry Sandusky molesting a boy on campus and that he fully conveyed what he had seen to two Penn State administrators.
Mike McQueary, speaking for the first time in public about the 2002 encounter in a Penn State locker room, said he believes that Sandusky was attacking the child with his hands around the boy's waist but said he wasn't 100 percent sure it was intercourse.
McQueary took the stand Friday morning in a Pennsylvania courtroom during a preliminary hearing for university officials Tim Curley and Gary Schultz, who are accused of lying to a grand jury about what McQueary told them.
District Judge William C. Wenner ruled late Friday that prosecutors do have probable cause to move forward with the cases against Curley and Schultz -- a decision that widely expected.
But the decision came at the end of a day of new testimony in the scandal that rocked Penn State University, it's football program, and the surrounding community. McQueary gave his first formal public statements and former coach Joe Paterno's testimony to a grand jury was read into the public record for the first time
McQueary's story is central to the case against Curley and Schultz. They testified to the grand jury that McQueary never relayed the seriousness of what he saw. The officials, and Penn State coach Joe Paterno, have been criticized for never telling police about the 2002 allegation. Prosecutors say Sandusky continued to abuse boys for six more years.
The lawyers for Curley and Schultz say the men are innocent.
McQueary spoke in a clear, firm and forceful voice, taking frequent sips of water during his two-hour testimony, reports CBS News investigative producer Pat Milton from inside the courtroom.
McQueary said he had stopped by a campus football locker room to drop off a pair of sneakers in the spring of 2002 when he heard slapping sounds in a shower and happened upon Sandusky and the boy.
He said Sandusky was behind the boy he estimated to be 10 or 12 years old, with his hands wrapped around the boy's waist. He said the boy was facing a wall, with his hands on it.
McQueary said he has never described what he saw as anal rape or anal intercourse and couldn't see Sandusky's genitals, but that "it was very clear that it looked like there was intercourse going on."
In its report last month, the grand jury summarized McQueary's testimony as saying he "saw a naked boy ... with his hands up against the wall, being subjected to anal intercourse by a naked Sandusky."
Under cross examination by an attorney for Curley, McQueary reiterated that he had not seen Sandusky penetrating or fondling the boy but was nearly certain they were having intercourse because the two were standing so close and Sandusky's arms were wrapped around the youth.
He said he peeked into the shower several times and that the last time he looked in, Sandusky and the boy had separated. He said he didn't say anything, but "I know they saw me. They looked directly in my eye, both of them."
McQueary said the entire encounter from when he first entered the locker room to when he retreated to his office lasted about 45 seconds.
McQueary said he reported what he saw to Paterno but never went to police.
He said he did not give Paterno explicit details of what he believed he'd seen, saying he wouldn't have used terms like sodomy or anal intercourse out of respect for the longtime coach.
He said Paterno told him he'd "done the right thing" by reporting the encounter. The head coach appeared shocked and saddened and slumped back in his chair, McQueary said.
Paterno told McQueary he would talk to others about what he'd reported.
Nine or 10 days later, McQueary said he met with Curley and Schultz and told them he'd seen Sandusky and a boy, both naked, in the shower after hearing skin-on-skin slapping sounds.
"I told them that I saw Jerry in the showers with a young boy and that what I had seen was extremely sexual and over the lines and it was wrong," McQueary said. "I would have described that it was extremely sexual and I thought that some kind of intercourse was going on."
McQueary said he was left with the impression both men took his report seriously. When asked why he didn't go to police, he referenced Schultz's position as a vice president at the university who had overseen the campus police
"I thought I was talking to the head of the police, to be frank with you," he said. "In my mind it was like speaking to a (district attorney). It was someone who police reported to and would know what to do with it."
Under cross-examination, McQueary said he considered what he saw a crime
"I tried to use my best judgment," he said. "I was sure the act was over." He said he never tried to find the boy.
Later, Thomas Harmon, the former chief of the Penn State police department, said Schultz didn't tell him about the shower allegation.
Paterno, Schultz and Curley didn't testify, but Judge Wenner read their grand jury testimony from January in weighing the case. The testimony was expected to be read into the record Friday afternoon.
Sandusky says he is innocent of more than 50 charges stemming from what authorities say were sexual assaults over 12 years on 10 boys in his home, on Penn State property and elsewhere. The scandal has provoked strong criticism that Penn State officials didn't do enough to stop Sandusky, and prompted the departures of Hall of Fame football coach Joe Paterno and the school's longtime president, Graham Spanier.
Sandusky on Tuesdayat the last minute. His lawyer said he was concerned the proceeding would be too one-sided and that prosecutors had agreed not to seek a bail increase.
Curley, 57, Penn State's athletic director, was placed on leave by the university after his arrest. Schultz, 62, returned to retirement after spending about four decades at the school, most recently as senior vice president for business and finance, and treasurer.
Meanwhile, The Patriot-News of Harrisburg has reported that McQueary's story changed when speaking in 2002 to Dr. Jonathan Dranov, a family friend. The newspaper report cited a source said to be familiar with Dranov's testimony.
"If this information is true, and we believe it is, it would be powerful, exculpatory evidence and the charges against our clients should be dismissed," Caroline Roberto, a lawyer for Curley, and Tom Farrell, the attorney representing Schultz, said in their statement.