(CNN) -- Jerry Sandusky, the former Penn State assistant football coach accused of sexually abusing boys over a 14-year period, is working with a private investigator in his quest to prove his innocence, his lawyer said Monday.
Attorney Joe Amendola said his client, who is free on $100,000 bail, is conducting his own investigation.
Besides the original attorney general's criminal inquiry, several other investigations have been launched tied to various aspects of Sandusky's case, including by Penn State and the U.S. Department of Education.
Sandusky, 67, is charged with 40 counts related to the alleged sexual abuse of eight young boys. He allegedly met the victims through The Second Mile, a charity that he founded.
The longtime Nittany Lions defensive coordinator previously said in an interview with NBC's Bob Costas that he has been falsely accused, saying that he only "horsed around" with kids in showers after workouts. Amendola also has consistently said that Sandusky is innocent.
The case has developed significantly since Sandusky's arrest, and subsequent release, this month.
Penn State Athletic Director Tim Curley, 57, and the school's vice president for finance and business, Gary Schultz, 62, were each charged with one count of felony perjury and one count of failure to report abuse allegations about Sandusky. Their preliminary court hearing is set for December 16 at the Dauphin County Courthouse in Harrisburg, according to a news release from the county.
In addition, Penn State President Graham Spanier and iconic head football coach Joe Paterno lost their jobs soon after Sandusky's arrest, following criticism that the football program and university in general did not adequately handle the matter when allegations arose years earlier.
Several other people have also subsequently come forward, saying they too were sexually abused by Sandusky.
They include an inmate in Oklahoma who said, in a handwritten letter to Penn State administrators, that he "was a victim of Jerry Sandusky decades ago," school spokeswoman Lisa Powers said Monday.
"They have turned the letter over to the (Pennsylvania) Attorney General for further investigation," Powers said by e-mail.
Meanwhile, the person identified as "Victim 1" in court documents tied to Sandusky has retained a pair of lawyers to represent him and his mother, the attorneys, Michael Boni and Slade H. McLaughlin, said Monday in a press release.
The grand jury report cited evidence that Sandusky -- who met the boy when he was 11 or 12 years old -- "indecently fondled Victim 1 on a number of occasions, performed oral sex on Victim 1 on a number of occasions and had Victim 1 perform oral sex on him on at least one occasion."
While he was the last of eight boys named in the grand jury reported to be allegedly assaulted, it was Victim 1's allegations that triggered the launch of the criminal investigation in 2008. While trying to shield her identity, his mother has spoken to some journalists, and the boy's psychologist Mike Gillum has spoken with CNN.
The lawyers said they'd now be the primary contacts for Victim 1 and his family, while also alluding to possible civil lawsuits against the former coach and others.
"We will protect their interests as they assist the prosecution in the criminal proceeding; we will deflect attention away from them; ... and, when the time is right, we will represent them in a civil action against Sandusky and others," the attorneys said.
Meanwhile, the charity that Sandusky founded -- and through which he met this alleged victim and several others -- issued a statement on Monday, urging its supporters to donate to the Pennsylvania Coalition Against Rape.
"The events reported over the past few weeks have saddened and horrified us," The Second Mile said in a statement. "We are determined to do all we can to help the survivors with the healing process."
The charity added that it is "continuing to review options for the next phase of our programs," in light of the Sandusky scandal. Its programs slated for December "will continue as scheduled."
CNN Contributor Sara Ganim contributed to this report.