Former Penn State graduate assistant Mike McQueary, left, is the key witness in the case against Jerry Sandusky, who is accused of sodomizing a 10-year-old boy in a Penn State locker room.

STATE COLLEGE — 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 e-mail 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 e-mail 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 to 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.

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.

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.