Deputy Attorney General Rod Rosenstein said Sunday that the decision to impanel a grand jury says nothing about the possibility of indictments. During an interview on "Fox News Sunday," Rosenstein explained: "In general, Chris, it doesn't say anything about the likelihood of indictments." "It's just a tool that we use like any other tool in the course of our investigations." WALLACE: We learned this week that special counsel Robert Mueller is taking his case to a grand jury. I know you can't and won't talk about the details of that case, but as a general proposition, does the fact that a prosecutor takes a case to a grand jury, what does that say about the likelihood of indictments? ROSENSTEIN: Chris, I'm — you are right that I'm not going to comment on the case. I'm not going to comment about whether Director Mueller has or hasn't opened a grand jury. You know, we read a lot about criminal investigations in the media and some of those stories are false. We just don't comment on investigations. That's important for a number of reasons. First of all, we don't want to disparage anybody who may be a subject of an investigation. Number two, we don't want to interfere with the investigation by — WALLACE: But I'm asking you a different question. What does it say when a prosecutor takes a case, in general, to a grand jury about the likelihood of indictments? ROSENSTEIN: In general, Chris, it doesn't say anything about the likelihood of indictments because we conduct investigations and we make a determination that at some point in the course of the investigation about whether charges are appropriate. WALLACE: And what's the advantage in terms of an investigation into taking a case to a grand jury? ROSENSTEIN: Many of our investigations, Chris, involve the use of a grand jury. It's an appropriate way to gather documents, sometimes to bring witnesses in, to make sure that you get their full testimony. It's just a tool that we use like any other tool in the course of our investigations. WALLACE: There are reports that Mueller has expanded his investigation to go into the president's finances. He was asked about that recently. (BEGIN AUDIO CLIP) MICHAEL SCHMIDT, THE NEW YORK TIMES: Mueller is looking at your finances and your family's finances, unrelated to Russia, is that a red line? MAGGIE HABERMAN, THE NEW YORK TIMES: Would that be a breach of what his actual — TRUMP: I would say yes. I would say yes. (END AUDIO CLIP) WALLACE: When you — now, I know I'm very dangerous territory here, but hear me out on this because I'm not asking about the investigation. When you appointed Mueller, and you were the one who did, you had to sign an order authorizing the appointment of a special counsel, and you said that he was authorized to investigate any coordination with Russia and — I want to put these words on the screen — any matters that arose or may arise directly from the investigation. My question is, does that mean that there are no red lines that Mueller or any special counsel can investigate under the terms of your order, anything he finds? ROSENSTEIN: Chris, the special counsel is subject to the rules and regulations of the Department of Justice, and we don't engage in fishing expeditions. Now, that order that you read, that doesn't detail specifically who may be the subject of the investigation — WALLACE: Right. ROSENSTEIN: — because we don't reveal that publicly. But Bob Mueller understands and I understand the specific scope of the investigation and so, it's not a fishing expedition. WALLACE: I understand it's not a fishing expedition, but you say any matters that arose or may arise directly from the investigation. In the course of his investigation of the issues that he is looking at, if he finds evidence of a crime, can he look at that? ROSENSTEIN: Well, Chris, if he finds evidence of a crime that's within the scope of what Director Mueller and I have agreed is the appropriate scope of the investigation, then he can. If it's something that's outside that scope, he needs to come to the acting attorney general, at this time, me, for a permission to expand his investigation. But we don't talk about that publicly. And so, the speculation you've seen in the news media, that's not anything that I've said. It's not anything Director Mueller said. We don't know who's saying it or how credible those sources are.