This allegedly took place in athletic buildings on Penn State's campus, as well as the Toftrees Golf Resort and hotels, including on trips to Florida and Texas to watch the Nittany Lions play at the Outback and Alamo bowls, respectively, Victim No. 4 testified.

Jurors were shown excerpts of letters Victim No. 4 said Sandusky wrote to him. In one, it states, "I know that I have made my share of mistakes. ... My wish is that you care and have love in your heart. Love never ends."

Defense attorneys had filed a motion earlier Monday seeking to keep out testimony involving prosecutors' allegations Sandusky exhibited "grooming behavior," including the letters to Victim No. 4.

The lawyers said they intend to offer expert testimony from a psychologist who "will explain that the words, tones, requests and statements made in the letters are consistent with a person who suffers from a Histrionic Personality Disorder," the documents said.

According to the National Institutes of Health, those with histrionic personality disorder "act in a very emotional and dramatic way that draws attention to themselves."

"The goal of a person suffering from this disorder in writing those letters would not necessarily be to groom or sexually consummate a relationship in a criminal manner, but rather to satisfy the needs of a psyche belabored by the needs of such a disorder," the defense lawyers write in their motion.

LaVar Arrington, a former Penn State star linebacker whom Victim No. 4 mentioned, wrote in The Washington Post on Tuesday that he "knew this young man fairly well but didn't grasp the full extent of what he was going through."

"He always seemed mad or kind of distant," Arrington wrote. "I remember distinctly asking him: 'Why are you always walking around all mad, like a tough guy?' "

Arrington had defended Sandusky when the allegations first surfaced, but offered his apology in Tuesday's article.

"I hate everything that has happened, and now I must admit I feel even worse, knowing what allegedly was happening so close to me, and that I was unaware," he wrote. "All I can do is hope that Victim #4 finds this entry and can see that I'm offering my sincerest apologies. I am so sorry this happened."

Prosecutors meanwhile say Gary Schultz, a former Penn State vice president who oversaw campus police, held a file that detailed alleged incidents pertinent to the investigation of Sandusky.

Schultz and Tim Curley, Penn State's former athletic director, have pleaded not guilty to charges of perjury and failing to report an alleged sexual assault of a child.

The file, which prosecutors say was initially withheld during the investigation, shows inconsistencies with what Schultz and Curley told a grand jury, according to court documents filed by prosecutors and obtained by CNN Tuesday.

"The Commonwealth is entirely justified in using those documents as evidence to support the charge of perjury against Schultz," the court documents say.

Prosecutors say e-mails from Schultz, Curley and others further contradict that testimony.

The firm representing Louis Freeh, an ex FBI Director investigating Penn State's handling of the scandal, said Tuesday that his office "discovered these e-mails in the course of its work."

"These e-mails were then provided to the State Attorney General, consistent with the investigation's prior commitment to share certain information," the firm said. "These materials will be fully discussed in the report to the Task Force, and beyond that Judge Freeh and the investigation team has no further comment."

In opening statements, defense lawyer Joe Amendola suggested his client would take the stand and say he routinely "got showers with kids" after working out.

Sandusky has always maintained his innocence, Amendola said, claiming his client's alleged victims had changed their stories and were questioned until authorities received the answers they wanted.

"A lot of people lied," Amendola said. Some of the alleged victims have civil attorneys, he noted, calling that unusual. Others, he said, have a financial interest in the case.

"One of the keys to this case, one of the keys to your perception ... is to wait until all the evidence is in," Amendola told jurors. "Some of it will be graphic ... it's going to be awful. But that doesn't make it true."

Tom Kline, an attorney for Victim No. 5, told reporters later that his client had no financial interest and "never sought this out," but considers it "an obligation of citizenship" to testify.

And Victim No. 4 said he's never talked with his lawyer, whom he said he hasn't paid "a dime," about being part of any civil lawsuit against Sandusky.

Amendola told jurors former Second Mile children will testify that Sandusky affected their lives in a positive way, and he later showed a letter to Victim No. 4 in which the former coach wrote "I'm proud of you and really care."

The defense lawyer also questioned some alleged victims' behavior, including one who went to a football game with Sandusky prior to his arrest.