DAVID GREENE, HOST:
The Justice Department has named former FBI Director Robert Mueller special counsel on the Russia investigation. It is now his job to explore whether there was collusion between the Trump campaign and Russia ahead of the U.S. election last year. To learn more about Mueller, we reached Mark Sullivan. He is former director of the U.S. Secret Service. He's on the line.
MARK SULLIVAN: Good morning.
GREENE: So I know your time in government overlapped with Robert Mueller. What's it like to work with him?
SULLIVAN: You know, Bob Mueller is just a really great, down-to-earth type of guy. I think if you talked to anybody who worked with Bob, I think the first thing they'd tell you is just he's very humble. He's not looking to bring attention to himself - outstanding character. He's a no-nonsense type of guy. He's somebody who's highly respected by everyone who worked with him.
GREENE: Not wanting to draw a lot of attention to him - does that suggest that we're not going to be hearing a lot from him? I mean, if there are news organizations, like ours, and members of the public who wonder where this investigation is going, we might just have to sit tight because he's going to do a lot of his work out of the public's eye.
SULLIVAN: Yeah, I think that's a hundred percent correct. Again, I think he's going to go in;. He's going to evaluate what it is he needs to do. He's going to evaluate his team. And you're not going to get any - I don't think anyway - I think he's just going to go in, be - do a professional job and conduct this investigation and take it to - take the time he needs to take to do the investigation and see where it takes him.
GREENE: He became director of the FBI at such an extraordinary moment that really, in many ways, changed his job, changed the job of the agency. It was just days before the Sept. 11 attacks. What do you remember about his leadership during that time?
SULLIVAN: Well, I think that he had a very calming influence over the organization, over the country. I think it's a time where you saw the FBI revamped their mission. And that was all at the direction of Bob.
GREENE: Would he relish a role like this based on what you know of him?
SULLIVAN: I think that Bob is the consummate public servant. When you look at his career, his life - you know, going from a - he was a highly decorated Marine. He was a litigator in private practice. But pretty much, he's always been in government, whether it was as a prosecutor, you know, a line prosecutor. He was, I think - I think he was the chief of the criminal division. He was a U.S. attorney - believe he might have been an assistant attorney general and then ultimately the FBI director. I just think he has such a commitment to public service and to his country. I just think this was an opportunity that he knew he couldn't turn down.
GREENE: A lot of people wonder if, since he officially still works in the chain of command that goes up to the president in this role, that there could be pressure at some point. I mean, President Trump could, in theory, even fire him or pressure the Justice Department to fire him. How would Mueller respond to that kind of pressure?
SULLIVAN: You know, I think Bob Mueller is a very apolitical type of guy. He's somebody who's experienced in working complicated investigations. As I said, I think that he's going to go in, and he's going to let this investigation go where it's - wherever it takes the investigation. He's not going to leave a stone unturned. I think that he would - will withstand any pressure, and he's going to do what he thinks is right.
GREENE: OK. Mark Sullivan - he worked with Robert Mueller during the Bush and Obama administrations. He was director of the U.S. Secret Service.
Thanks so much for joining us.
SULLIVAN: Thank you. Transcript provided by NPR, Copyright NPR.