"What do you think of this approach?" Curley allegedly writes to Spanier.

About two hours later, the Penn State president responds to Curley in another e-mail and copies Schultz. Spanier allegedly calls the plan "acceptable," but worries whether it's the right thing to do, according to two sources.

"The only downside for us is if the message (to Sandusky) isn't 'heard' and acted upon, and we then become vulnerable for not having reported it," Spanier purportedly writes.

"But that can be assessed down the road. The approach you outline is humane and a reasonable way to proceed," he adds.

The next afternoon, Schultz allegedly responds to the Penn State president and its athletic director. Schultz signs off on handling the matter without telling anyone on the outside, at least for the time being.

"This is a more humane and upfront way to handle this,' Schultz purportedly writes. But he makes clear Penn State should inform Sandusky's charity Second Mile "with or without (Sandusky's) cooperation."

As for telling child welfare authorities, he adds, "we can play it by ear."

No one reported the 2001 shower incident to authorities. A decade later, in 2011, a grand jury found no Pennsylvania law enforcement or child welfare agency was ever told.

"It was not only not humane to give Sandusky a pass, but inhumane towards young men who fell prey to him," said attorney Tom Kline, who represents Victim 5. About six months after the February 2001 incident witnessed by McQueary, Victim 5 was molested. On June 22, Sandusky was convicted of having unlawful sexual contact with Victim 5, among 44 other counts involving nine other boys.

Sources say that based on the e-mails and other documents, they could face additional charges. Spanier could also be charged, law enforcement sources and legal experts say.

As part of an ongoing grand jury investigation, state prosecutors are poring over the e-mails turned over by Penn State as part of its own investigation, led by former FBI Director Louis Freeh.

According to court papers, the government is also examining a Sandusky file left behind by Schultz. In a statement, Schultz's attorney Tom Farrell says Schultz, who retired in 2009, did not keep any "secret" files.

Prosecutors say the file was created, maintained and possessed by Schultz and assert that documents in the file are "inconsistent" with statements made by Schultz and Curley to a grand jury.

One inconsistency may involve Schultz's grand jury testimony stating the state's child welfare agency was notified about the 2001 shower incident. "My recollection would be ... (in 2002) ... that they were asked to look into this allegation," Schultz testified.

(During McQueary's grand jury testimony, the incident was believed to have occurred in 2002. But investigators later determined the incident happened in February 2001.)

He also testified any notes he "probably" took about the 2002 incident may have been destroyed when he retired in 2009.

Curley's grand jury testimony also appears inconsistent with the purported e-mails. In the messages, he refers to "a first situation" in 1998, yet he told a grand jury he wasn't aware of any other allegations of alleged sexual conduct involving Sandusky.

A prosecutor asked Curley: "Specifically, a 1998 report, did you know anything about that in 2002?" Curley responded: "No, ma'am."

Schultz and Curley, through their lawyers, consistently maintain McQueary didn't tell them about a sexual assault in 2001, and instead said McQueary described "inappropriate conduct" or horsing around.

McQueary has repeatedly testified he told Penn State officials he saw a boy with his hands up against a wall with Sandusky behind him and heard slapping, rhythmic sounds. He added that someone wouldn't have to be "a rocket scientist" to figure out what was going on.

A jury acquitted Sandusky of rape involving the 2001 incident, and instead found Sandusky guilty of several other counts involved in that shower incident including unlawful sexual contact.

Spanier's lawyer did not respond to calls from CNN seeking comment for this story.

According to Penn State's board of trustees, Spanier was fired last year because "he failed to meet his leadership responsibilities."

Shortly after his dismissal, Spanier issued a statement that said, in part, "I was stunned and outraged to learn that any predatory act might have occurred in a university facility or by someone associated with the university. ... I would never hesitate to report a crime if I had any suspicion that one had been committed."

In a statement to CNN, lawyers for Schultz and Curley said both men were doing the best they could about a report of "inappropriate conduct" by a man with a stellar reputation.