HARRISBURG — Former Penn State President Graham B. Spanier was charged today with hushing up child molestation allegations against Jerry Sandusky, making him the third school official charged in the alleged cover-up.

Prosecutors also added counts against the two former assistants, Timothy M. Curley and Gary C. Schultz.

Spanier is charged with perjury, obstruction, endangering the welfare of children and conspiracy, according to online court records. Curley and Schultz face new charges of endangering the welfare of children, obstruction and conspiracy, according to the records.

Pennsylvania Attorney General Linda Kelly and state police Commissioner Frank Noonan had a news conference at noon to discuss the charges, which were filed with a district justice outside Harrisburg.

Curley and Schultz have repeatedly asserted they are innocent, and at a news conference this summer Spanier’s attorneys insisted he was never told there was anything of a sexual nature involving Sandusky and children.

Curley, 58, the athletic director on leave while he serves out the last year of his contract, and Schultz, 63, who has retired as vice president for business and finance, were charged a year ago with lying to the grand jury that investigated the former Penn State assistant football coach and failing to properly report suspect child abuse. Their trial is set for January.

Spanier, 64, of State College, had been university president for 16 years when he was forced out as president after Sandusky’s arrest in November 2011.

Sandusky, who spent decades on the Penn State staff, was convicted in June of the sexual abuse of 10 boys over 15 years. He has maintained he is innocent and was transferred to a maximum security prison on Wednesday, where he is serving a 30- to 60-year sentence.