HARRISBURG -- The star prosecution witnesses against former Pennsylvania State University president Graham B. Spanier finally took the stand Wednesday, delivering neither bombshells nor a smoking gun but instead a fresh dose of uncertainty about when they knew Jerry Sandusky was a child predator and what they did about it.

Publicly testifying for the first time since they were charged in 2011, former athletic director Tim Curley and former vice president Gary Schultz told jurors they did not know Sandusky had sexually assaulted children and said they believed they acted appropriately after hearing reports in 1998 and 2001 that the former assistant football coach had showered with boys.

During nearly three hours of questioning, both men also seemed to do little to bolster prosecutors' contention that Spanier knew about Sandusky's crimes and failed to act on them or prevented others from doing so.

But Curley and Schultz agreed on one point: In hindsight, both said they should have done more.

"I felt I had been deficient in not reporting it myself," said Schultz.

Their testimony had been expected to be a cornerstone of the conspiracy and endangerment case against Spanier. Both men became government witnesses after striking deals last week and pleading guilty to a single endangerment count.

Instead, their testimony raised questions about whether Spanier's defense team, scheduled to begin presenting its case Thursday morning, will find it necessary to call the 68-year-old longtime university president as a witness, or merely argue that the prosecution failed to prove its case beyond a reasonable doubt.

Spanier has denied any wrongdoing; his lawyer told jurors in opening arguments he was being unfairly prosecuted for a judgment call.

Prosecutors had portrayed the three administrators as plotting in 2001 not to alert authorities after assistant football coach Mike McQueary reported seeing Sandusky sexually assault a boy in a locker-room shower on campus. Prosecutors say the administrators failed to act despite knowing that police had looked into a report in 1998 of Sandusky showering with a young boy.

Both Curley and Schultz said they thought reports that Sandusky had showered with young boys was inappropriate but not criminal.

"I thought Jerry had boundary issues, judgment issues that needed to be addressed," Curley testified.

He took the stand Wednesday morning and Schultz later in the afternoon; neither was in the courtroom when the other testified. And while portions of their accounts matched, each also contradicted the other at times.

Curley struggled at times to recall details of meetings or conversations with Spanier or Schultz.

Curley said he and Schultz had visited head coach Joe Paterno at his State College home in 2001 to hear what McQueary had told the coach. But Schultz testified that he didn't recall going to Paterno's house for that meeting and that he got his initial report on what happened from Curley.

Curley's testimony also raised questions about past statements by Paterno, who before he died said he had been unaware of any misconduct allegations against Sandusky until 2001.

Curley testified that he had told Paterno in 1998 that police had looked into the claim that Sandusky showered with a boy, but opted not to bring charges. He cited an email in which he said he had "touched base with the coach" and would keep him informed about the allegation.

Both men suggested they had not been led to believe McQueary witnessed a sexual attack in the shower.

Schultz said McQueary told them that he saw Sandusky standing behind a young boy with his arms wrapped around him -- and that both were naked.

But he said he did not recall McQueary claiming, as he has in the courtroom, that he heard skin-on-skin "slapping sounds."

The former vice president also testified that when he first described the incident to Spanier, he used the word horseplay because, he said, that's how Curley told him Paterno had described it.

Schultz also said he took notes from a 2001 meeting with Spanier and Curley, during which he noted that they discussed the 1998 shower incident. They then decided that child welfare authorities should be notified and that Curley would "take the lead" and speak with Sandusky. He testified that his notes reflected Spanier's "instructions."

But he said he soon became "disappointed and frustrated" by how slowly Curley was moving on the matter. He and Curley didn't interview McQueary until about 10 days after McQueary first reported the incident.

"Did Mike McQueary ever say what he saw was horseplay?" asked prosecutor Laura Ditka.

"No," Schultz replied.

Days after that meeting, Schultz said, Curley wrote an email to him and Spanier saying he wanted to hold off on alerting child welfare officials until he had had a chance to speak with Sandusky. All three men agreed that was the fairest way to handle the matter, he said. Authorities were never notified; instead they agreed to bar Sandusky from bringing children onto campus.

Schultz testified that the decision was "a mistake,"  seconds later adding: "We should have reported it, like the original plan."

Curley acknowledged that the men initially had intended to notify state welfare officials of the McQueary report but testified that he became "uncomfortable" with that plan after talking with Paterno.

Under questioning, Curley could not recall what Paterno said to him to make him feel uncomfortable. He also was unable to recall how Paterno reacted in 1998, when he said he told the head coach police had looked into the first Sandusky shower incident.

Both men acknowledged on cross-examination that they never conspired with Spanier to commit a crime or endanger children, and that they thought at the time that what they had done was responsible and legal.

Deputy Attorney General Patrick Schulte asked Curley if he ever sought to identify or find the boy McQueary saw in the shower.

"I did not," Curley said. "Looking back now, I should have."

Four of Sandusky's victims were assaulted after the 2001 McQueary report, an agent for the Attorney General's Office told jurors. Each later became a witness at his 2012 trial.

One of them briefly testified, telling the jury he was 11 when Sandusky assaulted him in a campus shower in 2002.