(CNN) -- A string of sexual child abuse charges against a former Penn State assistant football coach includes an alleged shower incident that two current university officials are accused of covering up, prosecutors said Saturday.
Jerry Sandusky, 67, who served 23 years as defensive coordinator for the Nittany Lions, allegedly engaged in fondling, oral sex and anal sex with young boys over a period of more than 10 years, according to an investigative grand jury's summary of testimony.
"This is a case about a sexual predator who used his position within the university and community to repeatedly prey on young boys," Pennsylvania Attorney General Linda Kelly said Saturday in announcing the charges.
In some cases, Sandusky, who maintains his innocence, promised the boys gifts or invited them to football games and sleepovers, according to the grand jury. Some of the incidents allegedly occurred in Penn State athletic facilities.
Sandusky, who retired from coaching in 1999, was founder of the Second Mile, a charitable organization that began as a group foster home "dedicated to helping troubled boys," the grand jury states.
"Through the Second Mile, Sandusky had access to hundreds of boys, many of whom were vulnerable due to their social situations," it added.
Also named in the grand jury report are Penn State Athletic Director Timothy Curley, 57, and Gary Schultz, 62, the university's senior vice president for finance and business, who face charges of one count of perjury each.
Curley and Schultz "allegedly failed to report the sexual assault of a young boy after the information was brought to their attention, and later made false statements to a grand jury that was investigating a series of assaults on young boys," Kelly said.
The two university officials are expected to surrender Monday.
Sandusky, who was arrested and released Saturday on $100,000 unsecured bail, faces seven counts of involuntary deviate sexual intercourse, and numerous other charges, including aggravated indecent assault and endangering the welfare of a child.
A preliminary hearing is scheduled for Wednesday, but defense attorney Joseph Amendola told CNN Johnstown affiliate WJAC he expects it be postponed in order for attorneys to have enough time to bring in witnesses.
Sandusky has known about the allegations for three years, the lawyer said.
"Jerry feels like because of his background and reputation it took a long time to reach this conclusion and he's been ready for it," Amendola told WJAC.
The grand jury investigation was initiated by the claims of one boy who alleged that Sandusky had "indecently assaulted" him and engaged in sex acts while the boy was a guest at his home, according to the attorney general.
The victim met Sandusky through the former coach's Second Mile charity, Kelly said. Sandusky allegedly used expensive gifts such as trips to professional and college games, golf clubs, a computer and money, Kelly said.
The relationship, which began in 2005 and lasted into 2008, included overnight stays at Sandusky's home, where touching led to sexual acts, according to Kelly and grand jury testimony.
"One of the most compelling and disturbing pieces of testimony in this investigation came from an eyewitness to a late-night sexual assault that allegedly occurred in March of 2002, in the locker room of the Lasch Football Building on the University Park Campus," Kelly said. "Hearing what sounded like sexual activity in the showers of a building that was supposed to be empty, a graduate assistant reportedly observed Sandusky sexually assaulting a naked boy who appeared to be about 10 years old."
The assistant reported the incident to head football coach Joe Paterno, who in turn alerted athletic director Curley, Kelly said.
Instead of reporting the incident to authorities, Curley and Schultz banned Sandusky from having children from Second Mile visit the football building, Kelly said.
Specifically, the grand jury found that Curley committed perjury in repeatedly denying that he had ever been told that Sandusky had engaged in sexual misconduct with a child, Kelly said.
"Assertions by Schultz that the allegations concerning Sandusky were 'not that serious' and that he and Curley 'had no indication that a crime had occurred' were in direct contradiction to other testimony and constituted perjury," Kelly wrote.
In all, the grand jury identified eight boys, ranging in age from about 8 to 14, who were the targets of similar sexual advances or assaults by Sandusky from 1994-2009. All of the victims first encountered Sandusky through Second Mile activities, Kelly said.
Authorities said they are continuing to search for additional victims and that the case remains active.
Penn State President Graham Spanier said in a statement that the allegations against the former coach are "troubling," and that the investigation is appropriate.
With regards to Curley and Schultz, Spanier said they have his "unconditional support."
"I have complete confidence in how they have handled the allegations about a former University employee," he said, adding that the charges are "groundless."
CNN's Stephanie Gallman contributed to this report.