Former Penn State Senior Vice President Gary Schultz also pleaded guilty to child endangerment, per Thompson.
The move comes just a week before all three men - Spanier, Schultz and Curley - were scheduled to stand trial on accusations they were criminally negligent in handling child-sex accusations against Sandusky in 2001.
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Curley, Schultz and Spanier handled a complaint from former Penn State graduate assistant Mike McQueary in 2001.
Sandusky, a longtime Paterno assistant, is now serving a 60 year sentence in prison for molesting 10 boys. With Schultz and Curley pleading guilty, Spanier is the only defendant left in the case, and it is now possible that Schultz and Curley will testify on behalf of the prosecution. One of Sandusky's sons, Jeffrey Sandusky, was recently arrested and charged with sexual assault of a minor. He was convicted in 2012 of 45 counts of sexual abuse of 10 boys, and is serving a 30- to 60-year state prison term.
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The 49ers put finding a quarterback at the top of their off-season to-do list after Colin Kapernick opted out of his contract. It looks like Cousins, whose name has appeared in trade rumors, finally is fed up with Washington and wants out.
Former Vice President Gary Schultz and former Athletic Director Tim Curley each took a plea bargain that - if accepted by the judge - will carry a penalty of up to five years in prison and a $10,000 fine.
Shortly after Sandusky's arrest, Hall of Fame football coach Joe Paterno was sacked.
All three men are accused of failing to report allegations of abuse against coach Jerry Sandusky when first made aware of them a decade earlier.
In the fall of 2016, McQueary was awarded more than $12 million in a civil lawsuit against Penn State that claimed defamation, intentional misrepresentation and violation of the state's whistleblower law. The wins were later restored. Paterno reported the information to Curley, his supervisor, and Curley and Schultz never reported the incident to the authorities.
The university and its football program faced NCAA sanctions in the fallout of Sandusky's charges and conviction.