TUCSON, Ariz. -- Arizona athletic director Dave Heeke told ESPN that he stands behind head men's basketball coach Sean Miller after Wildcats assistant Emanuel "Book" Richardson was one of four high-major assistant coaches arrested as part of an FBI probe into corruption within college basketball.

"I have utmost respect for Sean," Heeke said in an exclusive interview with ESPN. "He's a guy of high integrity who has run this program in an honest and clear and upfront way. I have no reason to not believe he's done that always. I fully am in support of Sean and the program he's run."

Arizona athletic director Dave Heeke told ESPN that he stands behind head men's basketball coach Sean Miller. Stephen R. Sylvanie/USA TODAY Sports

The university suspended Richardson on Sept. 26 after federal agents arrested him at his home in Tucson. The school then initiated the dismissal process against Richardson, who has been charged with conspiracy to commit bribery, solicitation of bribes by an agent of a federally funded organization, conspiracy to commit honest services fraud, wire fraud conspiracy and travel act conspiracy. Richardson is accused of accepting $20,000 in bribes from a sports agent, some of which he kept for himself and some of which he provided to at least one prospective high school recruit. In exchange for the bribe, Richardson agreed to use his influence to send Wildcats to the sports agent and a financial advisor.

"I think we're all confused at why someone so closely aligned with all of us here at the University of Arizona would do something like that," Heeke said of Richardson. "That's hard to take.

Miller declined to comment to ESPN.

"Anytime your program and the university were called into question, that's hard," Heeke added. "Sean has been terrific to work with, he has been incredibly forthcoming and forthright with all the things we wanted to do. He and I have continual, open conversations so I feel really good."

"I know we've been diligent from a compliance perspective and that Sean certainly is," he added. "I have all the confidence in the world that we've done the right things and people knew what's right and what's wrong."

Heeke took over for Greg Byrne in April after Byrne left for a similar position at Alabama. Heeke was previously the AD at Central Michigan, but spent nearly two decades as an administrator at Oregon.

Heeke said the overall process, which includes an independent, internal investigation charged by the school president and the regents and also a separate internal firm that is working with the NCAA, has been slow-moving.

"I don't know how long it will take," Heeke said "We're taking it day by day, trying and do exactly what we can do based on the federal investigation, based on where the NCAA wants to go. How they begin to move forward."

"We're working with our compliance staff, navigating through and working with the NCAA on all of those pieces," he added. "This is going to move from a federal investigation and then there's going to be ramifications on how those may connect to the NCAA. We're trying to be proactive, trying to understand as much as we can how will this impact our program. What will we need to do per NCAA recommendations, guidance -- but it's been real slow, real careful -- which I agree with."

Arizona boasts a team this season that is ranked in the preseason top five and has a chance to go to the Final Four for the first time since 2001. The Wildcats, who open on Nov. 10 against Northern Arizona at home, brought back Allonzo Trier, Rawle Alkins, Dusan Ristic and Parker Jackson-Cartwright -- and added one of the nation's top freshmen classes, highlighted by 7-footer DeAndre Ayton.