STATE COLLEGE, Pa. — A day after the former Penn State assistant football coach who is charged with sexual abuse of boys declared his innocence in a television interview, an email surfaced from a key witness against him, saying he stopped an alleged attack in the team’s showers.

Mike McQueary, the graduate assistant who a grand jury report said saw Jerry Sandusky allegedly sodomizing a boy in the locker room, said he stopped the act and went to police. That added confusion to the already emotionally raw situation that has enveloped Penn State University and resulted in the firing of coach Joe Paterno, the ousting of president Graham Spanier and charges of perjury against the athletic director and a former senior vice president.

The Nov. 8 email from McQueary to a friend, made available to The Associated Press, said: “I did stop it, not physically … but made sure it was stopped when I left that locker room … I did have discussions with police and with the official at the university in charge of police …. no one can imagine my thoughts or wants to be in my shoes for those 30-45 seconds … trust me.”

McQueary is a former player and current assistant coach who was placed on indefinite paid leave last week after school officials said he had received threats. Emails sent to him seeking comment were not immediately returned.

He told the friend that he felt he was “getting hammered for handling this the right way … or what I thought at the time was right … I had to make tough impacting quick decisions.”

The grand jury report issued Nov. 5, the day Sandusky was charged with 40 criminal counts for alleged sexual abuse against eight boys over 15 years, goes into considerable detail about the March 2002 incident. McQueary was putting sneakers into his locker late on a Friday night when, the jury said, he saw Sandusky having sex with a young boy.

He left, “distraught,” and contacted his father and then head coach Joe Paterno, jurors said. McQueary later met with athletic director Tim Curley and vice president Gary Schultz to describe what he had seen, the grand jury said. Curley and Schultz are charged with not alerting authorities to the report and lying to the grand jury. Paterno lost his job last week, but has not been charged and is not considered a target of investigators, state prosecutors have said.

As a result of the scandal, Curley and Schultz have left their posts, and university president Graham Spanier was also forced out of his job. U.S. Steel said Tuesday that Spanier has resigned from its board, where he had been a director since 2008.

On Wednesday, Penn State named Dr. David M. Joyner, an orthopedic surgeon who got his bachelor’s degree and medical degree from the university, as acting athletic director.

Joyner’s position on the school’s board, where he has been a trustee since 2000, is being suspended as he takes on the new duties.

On Monday night, Sandusky said in an NBC television interview that he showered with and “horsed around” with boys but was innocent of criminal charges, a statement that has stunned legal observers. Sandusky’s comments, they said, could be used by prosecutors trying to convict him of child sex-abuse charges.

“Mr. Sandusky goes on worldwide television and admits he did everything the prosecution claims he did, except for the ultimate act of rape or sodomy? If I were a prosecutor, I’d be stunned,” said Lynne Abraham, the former district attorney of Philadelphia. “I was stunned, and then I was revolted.”

Abraham, who led a grand jury probe involving 63 accused priests from the Philadelphia archdiocese, was retained this week to lead an internal investigation of The Second Mile, the children’s charity founded by Sandusky, from which he allegedly culled his victims.

Sandusky told NBC News’ “Rock Center” he was not a pedophile, but in retrospect should not have showered with boys.

“I could say that I have done some of those things. I have horsed around with kids. I have showered after workouts. I have hugged them, and I have touched their legs without intent of sexual contact,” Sandusky told Bob Costas. “I am innocent of those charges.”

When Costas asked him whether he was sexually attracted to underage boys, Sandusky replied: “Sexually attracted, no. I enjoy young people, I love to be around them, but, no, I’m not sexually attracted to young boys.”

Sandusky apparently decided to talk to Costas by phone Monday at the last minute, with the blessing of his attorney, Joseph Amendola, who was in the studio.

“What was especially astonishing about Sandusky’s interview is — and this will be the big moment in court — is when he stumbled over the question about whether he was sexually attracted to children,” said crisis management expert Eric Dezenhall, who runs a Washington consulting firm. “That may not be legal proof that he’s guilty, but it is certainly not helpful, to struggle with the question.”

The state grand jury investigation that led to Sandusky’s arrest followed a trail that goes back at least 13 years, leading to questions from some quarters about whether law enforcement moved too slowly.

The grand jury report detailed a 1998 investigation by Penn State police, begun after an 11-year-old boy’s mother complained that Sandusky had showered with her son in the football facilities. Then-District Attorney Ray Gricar declined to file charges.

Another apparent missed opportunity came in the 2002 incident that McQueary reported to Paterno.

The case took on new urgency about three years ago, when a woman complained to officials at her local school district that Sandusky had sexually assaulted her son. School district officials banned him from school grounds and contacted police, leading to an investigation by state police, the attorney general’s office and the grand jury.

Gov. Tom Corbett took the case on a referral from the Centre County district attorney in early 2009 while he was serving as attorney general.

He bristled Tuesday when asked whether it was fair for people to criticize the pace of the probe.

“People that are saying that are ill-informed as to how investigations are conducted, how witnesses are developed, how backup information, corroborative information is developed, and they really don’t know what they’re talking about,” he told reporters.

The attorney general’s office declined to comment on the pace of the investigation.

The Patriot-News of Harrisburg reported Monday that only one trooper was assigned to the case after the state took it over in 2009. After Corbett became governor early this year and his former investigations supervisor in the attorney general’s office, Frank Noonan, became state police commissioner, seven more investigators were put on it, the newspaper said.

Noonan’s spokeswoman, Maria Finn, said Tuesday that manpower was increased in the case this year, but she could not confirm the numbers reported by the newspaper.

“The investigation, at the time, was gaining momentum,” Finn said. “There were more leads, there were more things to do at that point. It’s not that the state police weren’t doing anything and Noonan comes in and changes things.”

With the case now drawing global media attention and potential civil litigants watching from the sidelines, Sandusky went on the offensive in the NBC interview.

“I would knock my client over the head with a two-by-four before I would let them do it, but it cuts both ways,” said criminal defense lawyer Mark Geragos, who represented O.J. Simpson and other celebrity defendants. “If prosecutors use it, it can end up being testimony without cross examination.”

He called the Penn State matter an unusual case that may call for unusual tactics, given the “instantaneous uproar to convict the guy.”

Penn State’s trustees have hired the public relations firm Ketchum, which through corporate communications director Jackie Burton said only that “the details of all our client assignments are confidential.”

Paterno, who authorities say fulfilled his legal responsibilities and is not considered an investigative target, has hired Washington lawyer Wick Sollers. Sollers told the AP on Tuesday he was “not in a position to comment just yet.”

Also Tuesday, lawyers for Schultz and Curley issued a statement in which they said it was “a travesty” that prosecutors sought to delay their clients’ preliminary hearing until next month.

“Mr. Curley and Mr. Schultz are anxious to face their accusers, clear their good names and go on with their lives,” said attorneys Caroline Roberto and Tom Farrell.

The attorney general’s office declined to comment.

The State Employees’ Retirement System released records Tuesday showing Paterno’s long service at the university theoretically puts him in line for a pension of more than $500,000 a year, according to an Associated Press analysis. The formula used to determine benefits makes him eligible for a pension equal to 100 percent or 110 percent of the average of his three highest-salary years, although there are other factors that will influence his final amount, including how much he withdraws in a lump sum, legal limits to benefits and whether he designates a survivor to receive benefits after he dies.

The New York Times reported Tuesday night that Paterno transferred full ownership of his house to his wife, Sue, for $1 in July. The couple had previously held joint ownership of the house. Paterno’s attorney Wick Sollers told the paper in an e-mail that the transfer had nothing to do with the scandal but was part of an ongoing “multiyear estate planning program.”

Momentum appears to be building among state lawmakers for a legislative response to the legal issues raised by the investigation. State Rep. Eugene DePasquale, D-York, called on Corbett to appoint a special investigator to look for answers that fall outside the criminal investigation. Rep. Jake Wheatley, D-Allegheny, said legislative leaders should appoint a joint House-Senate committee with subpoena power to review state law that addresses mandatory reporting of suspected child abuse.

Sandusky’s next court date is Dec. 7, when he is due for a preliminary hearing in which a judge would determine if there’s enough evidence for prosecutors to move forward with the case.