Updated at 8:36 p.m. ET: Pennsylvania prosecutors are considering criminal charges against former top Penn State University officials for allegedly concealing what they knew about the conduct of former assistant football coach Jerry Sandusky, law enforcement told NBC News.

As Sandusky's trial began Monday on 52 counts alleging that he abused 10 boys over 15 years, the sources said investigators had obtained new evidence, including internal university email messages and other documents.

Prosecutors made their first public reference to the material in a court filing Monday, saying they included a file on Sandusky that was “created, maintained and possessed” by former Penn State Vice President Gary Schultz.

In addition, prosecutors said, the recently discovered emails “contradict” the testimony of Schultz, former athletic director Tim Curley “and others” before a grand jury about what they knew about an allegation of possible sexual misconduct by Sandusky.

Full coverage of the Jerry Sandusky trial

A spokeswoman for Curley and Schultz said their lawyers had not yet seen the new filing by prosecutors and couldn’t comment on it. Both men were charged with perjury for their testimony regarding Sandusky last November.

Legal sources tell NBC the emails and documents were recently discovered by investigators for former FBI director Louis Freeh, whose firm has been hired by Penn State to conduct an internal investigation into the school’s handling of the Sandusky matter.

The documents, the sources say, show that former university President Graham Spanier and others discussed whether they were obligated to tell authorities about a 2001 allegation involving a late-night encounter in a Penn State shower room between Sandusky and a young boy, both of whom were naked.

The documents allegedly show that university officials even did legal research on whether such conduct might be a crime. But in one email exchange, Spanier and Schultz agreed that it would be "humane” -- to Sandusky -- not to inform social services agencies, two sources said.

Spanier, who was fired last November, hasn't been charged in the investigation. He recently sued Penn State seeking access the emails, saying he needed to inspect them to “refresh his recollection” before granting an interview to Freeh’s investigators. His lawyers did not respond to a request for comment.

The allegation had come from then-graduate assistant Mike McQueary, who testified he saw Sandusky in a Penn State shower room with a young boy committing what he thought was a sexual act. He was so disturbed, he said, that he called late Penn State coach Joe Paterno at home the next morning. Both Schultz and Spanier testified they didn’t report the McQueary allegation because they viewed it as an account of mere “horsing around” rather than sexual abuse.

McQueary — who is expected to testify for the prosecution at Sandusky's trial — originally testified to a grand jury that he saw Sandusky in the shower with a young boy in March 2002. An email revealed Monday indicates that Spanier, Schultz and Curley discussed what McQueary allegedly saw and whether to report it more than a year earlier.

In a statement to NBC News on Sunday, lawyers for Schultz and Curley said "the information confirms that Tim Curley and Gary Schultz conscientiously considered Mike McQueary's reports of observing inappropriate conduct, reported it to the University President Graham Spanier and deliberated about how to responsibly deal with the conduct."

Schultz, who headed the campus police at the time, previously testified to a grand jury that he knew about another alleged incident involving Sandusky and a young boy in a shower in 1998. That report was investigated by local authorities but never led to charges.

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Updated at 7 p.m. ET: A 28-year-old man testified Monday that former Penn State University assistant football coach Jerry Sandusky treated him "like his girlfriend" for more than two years, showering him with gifts he was afraid he would lose if he told anyone about Sandusky's increasingly sexual behavior.

Sandusky, 68, denies all 52 counts alleging that he abused 10 boys over 15 years. Two grand jury reports accused him of having used his connection to one of the nation's premier college football programs to "groom" the boys —whom he met through his Second Mile charity for troubled children — for sexual relationships.

Earlier, on the opening day of his trial, Sandusky's attorney appeared to surprise prosecutors by listing Sandusky as a possible witness in his own defense.

The trial before a jury of seven women and five men heard opened in Centre County Court in Bellefonte, Pa., culminating months of breathless coverage that led to the firing of head coach Joe Paterno, who won more games than any other major college football coach in history, many of them with Sandusky at his side.

Paterno died in January, a few weeks after the Penn State Board of Trustees dismissed him for not having done enough to stop Sandusky's alleged abuse.

The first of eight alleged victims expected to testify — identified as alleged victim No. 4 — said he endured more than 40 "very uncomfortable" incidents involving Sandusky during the two years, when he was 12 and 13 years old.

(Although the men are being identified by name in court, NBC News and msnbc.com do not identify the victims of alleged sexual assaults.)

NBC: Former Penn State president could face charges in Sandusky case

Full coverage of the Jerry Sandusky trial

The behavior progressed from mutual showers in the Penn State coaches' locker room to hugging and caressing to rolling around together on the floor.

Eventually, the shower incidents progressed to Sandusky's placing the man's hand on his genitalia, said the man, who went on to describe more graphic behavior, including attempted sexual penetration.

In rides in his car, Sandusky would put the man's hand on his knee, "basically like I was his girlfriend," which he said "freaked me out."

"I could not stand it, and it happened almost every time I was in the car" with Sandusky, he said.

The man described similar behavior that he said he witnessed with other children.

At a summer camp at the beach, Sandusky would throw children up in the air in the water, "just like you do with a little kid, but he was grabbing them more about the buttocks area," the man said. "It was like brushing over your genitals."

Among the gifts he said Sandusky gave him were hockey sticks, golf clubs, a snowboard, Penn State football jerseys and a cherished spot on the sideline during football games. One time, he said, Sandusky gave him money to buy marijuana, which he said he smoked in front of Sandusky in his car.

The witness said those were things he desperately wanted but was afraid he would lose if he blew the whistle.

"This was something good happening. I never had a father figure, and I'm liking everything I'm getting," he said, adding that he also feared being teased by classmates if they learned that he was "being molested by Jerry."

The witness said under cross-examination that he regretted not having come forward earlier. Had he done so, he said, he might not feel responsible "for these other victims being molested." 

Sandusky attorney targets accusers
Amendola aggressively questioned the young man about his finances, part of a strategy he introduced in his opening statement, when he painted the eight alleged victims as troubled youths out for a big payday in court.

"You saw those eight photos," Amendola said, referring to photographs of the eight accusers as young boys that the prosecution had presented in its opening statement.

"Cute kids — why would they lie?" Amendola asked. "Folks, I don't know, when it comes to money. ...The evidence is going to show that six of these eight young men who are going to testify have sued. The evidence will show these young men have a financial interest in this."

Amendola noted that as long ago as 1998, local prosecutors had declined to bring charges against Sandusky.

"Jerry Sandusky has always said that he is innocent," Amendola said. "The testimony is going to be awful, but that doesn't make it true, and that's the bottom line."

Moreover, the eight alleged victims were already troubled as youths, he suggested, saying they knew Sandusky in the first place only because educators and government agencies had referred them to Second Mile because "they had issues."

Alleged victim No. 4 acknowledged that he was referred to Second Mile by a school guidance counselor at his school because "I got in trouble a lot" outside of class.

Judge refuses to dismiss Sandusky charges

But in his opening statement, Joseph McGettigan, the deputy state attorney general who is leading the prosecution, said the case was about "systematic behavior by a predator."

All of the witnesses are now adults, but McGettigan asked the jurors to "bring your insight (and) understanding of the way children experience things and react to things."

"They were boys. They didn't understand why this happened to them," he said.

McGettigan also indicated that prosecutors would call Michael McQueary to testify, answering one of the key pretrial riddles.

McQueary, a former Penn State assistant coach, told a grand jury that he witnessed Sandusky assaulting a boy in a shower in a locker room and that he told Paterno about the incident.

But McQueary's accounts of the incident have varied. For example, he testified that he was certain that the incident took place in March 2002 and that he immediately reported it to university officials. But the prosecution says it occurred in February 2001 — more than a year earlier — a discrepancy the defense is sure to highlight.

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