Floyd also has taken USC's once-lackluster basketball program to new heights. His signing of Mayo in 2006 was an eye-popping coup, although the guard bolted for the NBA after one season.
Carroll, Floyd and USC Athletic Director Mike Garrett have not responded to interview requests.
Last week, at the opening event of a seven-stop "Coaches Tour" for boosters, Carroll and Floyd sidestepped the one question from the Irvine audience about the NCAA's investigation. Carroll said scrutiny was the price "for being on top." Floyd stayed mum.
USC general counsel Carol Mauch Amir says it is Sample's policy not to comment on NCAA probes. In response to repeated inquiries by The Times, Mauch Amir said in a written statement that the university has been "vigorously investigating" all the allegations with the association and Pacific 10 Conference, and that the cooperative effort has included joint interviews with nearly 50 witnesses.
The school would have participated in more interviews but had been excluded from them, in some instances by the interviewee's attorneys, Mauch Amir said.
"We continue to operate under the fundamental American right that the accused is innocent until proven guilty, so we are working diligently to ensure that we have all the facts before reaching any conclusions," she added. "Our decision not to respond publicly to the allegations made in the media against USC, our coaches and our student-athletes simply reflects our responsibility to protect the integrity of the investigative process and to comply with all NCAA regulations."
Mauch Amir would not elaborate on her statement.
If USC has adopted a wait-and-see attitude in the investigation, it could be hoping that any misconduct did not extend beyond the agents and players, leaving the university in the clear, one expert on NCAA investigations said.
"The temptation there is greater to just let it play out and see if it comes back to you," said the expert, who asked not to be named because of his sensitive work with schools.
He said another possibility is that USC was waiting to learn if the NCAA unearthed anything that would contradict what the coaches and other staff members told school officials.
NCAA bylaws forbid schools from publicly disclosing information from the association's investigations until the probes are complete. But colleges are not barred from going public with their own findings, including material that might exonerate the school, NCAA officials say.
The bylaws also state that if a college or individual involved in an NCAA investigation makes information public, then the school, the individual or the association "may confirm, correct or deny the information."
"We don't put a gag order on a school," said NCAA spokeswoman Stacey Osburn. "And they can do their own complete investigation. . . . It's an incredibly common practice for schools to self-impose penalties."
A notable example involved the University of Oklahoma, where administrators in 2006 quickly dismissed two starting football players who allegedly accepted pay from a car dealer for work they didn't perform. The NCAA still penalized the university for not monitoring the athletes more closely, but its appeals committee later eased the punishment, citing in part the school's prompt removal of the players.
Dave Czesniuk, operations director for Northeastern University's Sport in Society program, which offers instruction in athletics leadership and ethics, said that "transparency is of huge importance" for schools in USC's straits, and that campus presidents should lead the search for truth.
"Do you always just take this reactionary approach, and just have damage control? No," Czesniuk said. "What a lot of presidents would do is get right at it, just for the simple sake of getting control of their own backyard."
Lake and Michaels have said they gave Bush and his family a total of about $300,000 in inducements as part of an arrangement for the player to work with them after he joined the NFL.
Now with the New Orleans Saints, Bush has denied any wrongdoing but reportedly has refused to be interviewed by the NCAA. His attorney did not respond to interview requests from The Times.
Lake is suing Bush over the purported marketing deal. Bush has settled a lawsuit brought by Michaels.
Last October, USC attorney Kelly Bendell sent a letter to attorney Watkins requesting that Lake, his sister and mother submit to interviews with the school and Pac 10 officials. The letter said USC "was not allowed to participate" in NCAA interviews of the three but did not specify who excluded the school or why.
Asked about the letter, Watkins told The Times that he responded to Bendell and had been prepared to make his client available for an interview, but she never got back to him. Mauch Amir declined to discuss the letter, as did a Pac-10 official.