(CNN) -- Here is a timeline of the Penn State child sex abuse scandal:
WARNING: CONTAINS GRAPHIC INFORMATION
1977 -- Penn State football defensive coordinator Jerry Sandusky founds "The Second Mile," a charity to help troubled youths.
1994-1997 -- According to the grand jury report, Sandusky allegedly engages in inappropriate conduct with three different boys he met separately through the Second Mile program. One boy was 7 or 8, another was 10, and the third was 12 or 13 at the time. According to the grand jury report, the now-adult men said Sandusky engaged in inappropriate conduct ranging from touching to outright sexual encounters, including several incidents during the nights before Penn State football home games, when the team, staff and boys Sandusky had allegedly invited were staying at a hotel.
1998 -- Penn State police and the Pennsylvania Department of Public Welfare investigate an incident in which the mother of an 11-year-old boy reported that Sandusky had showered with her son and may have had inappropriate conduct with him. In a June 1, 1998, interview with investigators from both agencies, Sandusky admits showering naked with the boy, admitting that it was wrong and promising not to do it again, according to the grand jury report. The district attorney advises investigators that no charges will be filed and the university police chief instructs that the case be closed, according to the testimony included in the grand jury report from the police detective who investigated the incident.
1999 -- Sandusky retires from Penn State after coaching there for 32 years, but stays on as a volunteer and retains full access to the campus and football facilities.
2000 -- Sandusky allegedly showers with a young boy and tries to touch his genitals during overnight stays at the coach's house, according to the now 24-year-old man's testimony included in the grand jury report.
2000 -- Tim Calhoun, a janitor at the Lasch Football Building on the Penn State campus, tells his supervisor and another janitor that he saw Sandusky performing oral sex on a young boy, according to the grand jury report. A second janitor reports that he saw Sandusky and a boy leave a shower room and walk out of the building hand in hand. No one reports the alleged incidents to university officials or law enforcement, according to the grand jury report.
March 2, 2002 -- According to the grand jury report, a graduate assistant allegedly tells Head Coach Joe Paterno that he saw Sandusky in the locker room shower the night before, performing anal sex on a young boy he estimated to be 10 years old.
March 3, 2002 -- Paterno reports the incident to Athletic Director Tim Curley, saying the graduate assistant had seen Sandusky "fondling or doing something of a sexual nature to a young boy," according to the grand jury. Later, the assistant is summoned to a meeting with Curley and Senior Vice President for Finance and Business Gary Schultz..
While the assistant later insisted to the grand jury that he told Curley and Schultz that he saw Sandusky and the boy engaged in anal sex, Curley and Schultz told the grand jury they had not been told of such an allegation. Instead, Curley said he had the impression the conduct amounted to nonsexual "horsing around." Schultz said he couldn't remember details, but seemed to recall that "Sandusky might have inappropriately grabbed the young boy's genitals while wrestling," according to the grand jury. Sandusky's locker-room keys are confiscated, he is told not to bring his Second Mile participants to campus, and the incident is reported to the charity, but no law enforcement investigation is launched, according to the grand jury.
2002 -- The Second Mile learns of the alleged shower incident. Curley tells the charity that "the information had been internally reviewed and that there was no finding of wrongdoing," the group said in a statement Monday.
2005 or 2006 -- Sandusky allegedly befriends another Second Mile participant, whose allegations would form the foundation of the multiyear grand jury investigation.
2006 or 2007 -- A wrestling coach at the high school where Sandusky is volunteering allegedly surprises Sandusky and a boy "lying on their sides, in physical contact, face to face on a mat" in a cramped weight room. Sandusky jumps to his feet and tells the coach the two were just working on wrestling moves, the coach later recalls in grand jury testimony. As time goes on, Sandusky allegedly begins to spend more time with the boy, taking him to sporting events and giving him gifts, including golf clubs, a computer, cash and clothes. During this period, according to the grand jury report, Sandusky allegedly performs oral sex on the boy more than 20 times, and the boy performs oral sex on him once.
2008 -- The boy breaks off contact with Sandusky. Later, his mother calls the high school to report her son had been sexually assaulted, and the principal bars Sandusky from campus and reports