Curley has maintained he was never made aware of the severity of Sandusky's alleged behavior.
In a motion filed Monday, his attorney argued that without testimony from Paterno, who died of lung cancer Jan. 22, the state could no longer prove its case. She also sought dismissal of the reporting charge, arguing that the law under which prosecutors charged her client did not exist at the time of the alleged crime.
"With the death of Mr. Paterno, the prosecution's . . . case clearly fails to establish the independent corroborative evidence as required," lawyer Caroline Roberto wrote.
Paterno lost his job in the fallout from the sex-abuse scandal but was not criminally charged.
In testimony before a grand jury last year, he testified that Mike McQueary, then a graduate assistant, told him that he had seen something "sexual in nature" between Sandusky and a boy. Paterno told grand jurors he conveyed the same story to Curley.
But because defense lawyers never had a chance to cross-examine Paterno, that grand jury testimony cannot be used at trial.
To secure a perjury conviction, prosecutors will have to offer some other corroborating evidence to McQueary's version of events.
Paterno may not loom as large in the case against former university vice president Gary Schultz, who faces similar charges.
McQueary's father testified at a preliminary hearing in December that he had subsequent discussions with Schultz about his son's story.
That could provide enough corroboration to prove the former administrator lied about what he knew, veteran prosecutors have said.
But both men could benefit from the distinction Roberto drew on the failure-to-report law.
As it stood in 2002, the law only required individuals to report abuse allegations made directly to them by children they came in contact with in the course of their duties.
Lawmakers tightened the statute in 2007 to require anyone who comes into contact with children through his or her job to report reasonable suspicions of abuse, whether directly reported by the victim or not.
But, Roberto said, Curley cannot be prosecuted under a "statute which was not in effect at the time of the alleged illegal conduct."
Lawyers have deployed a similar argument in the case of a ranking official in the Roman Catholic Archdiocese of Philadelphia accused of enabling two priests who allegedly molested boys in the 1990s.
Last month, Msgr. William J. Lynn's defense took the unusual step of asking the Pennsylvania Supreme Court to intervene in the case before the trial court could rule on a similar motion. The request is pending.
Prosecutors in the Penn State case have yet to respond to Curley's motion.
In separate developments Monday, Cleland, the presiding judge in Sandusky's case, issued a set of rulings that favored the accused former coach.
Chief among them: an order denying prosecutors' request for out-of-county jurors to try the case.
At a hearing Friday in Centre County, government lawyers argued that overwhelming publicity and the unique role Penn State plays in the community would make it impossible to find impartial jurors in the community.
Citing Sandusky's own preference for local jurors, Cleland decided to first try to impanel a jury from Centre County before looking in other parts of the state.
He also granted Sandusky's request for supervised visits with his grandchildren and denied a separate government motion seeking to confine the former coach inside his home while he remains under house arrest.
"We are happy with the outcome," Sandusky's attorney, Joseph Amendola, wrote in an e-mail Monday. "We realize, nevertheless, a number of difficult legal battles lie ahead of us."
Sandusky has denied charges he molested at least 10 boys he met through the Second Mile, a charity for underprivileged youth he founded in the 1970s.
He is scheduled to take his case to trial May 14.
Contact staff writer Jeremy Roebuck at 267-564-5218, firstname.lastname@example.org, or @jeremyrroebuck on Twitter.
Inquirer staff writer John P. Martin contributed to this article.