Transcript for GOP senator on Khashoggi murder: 'A smoking gun would certainly help'

Let's now turn to Roy blunt. He also serves on the senate intelligence committee. I want to turn back to Saudi Arabia. You heard congressman Schiff saying what he thinks should happen regarding the khashoggi report. Should the president issue sanctions on the crown prince? Like Adam we had a briefing this week. I can't really talk about that briefing. I do think that it won't hurt here for another few days to pass. The president says he'll have some conclusions by Tuesday on this. Certainly the way you look at Saudi Arabia and the way it runs, it's hard to imagine something like this could happen without the crown prince knowing. I don't know that we absolutely know that yet. Just from reading the reports in the "Washington post," we heard about phone calls that were intercepted. I know you can't talk about it. We heard phone calls intercepted between the prince and his brother. We heard about tapes inside the Saudi consulate in Turkey. What more is needed? The same question that I asked congressman Schiff. There doesn't appear to be a smoking gun, but there's a lot of evidence piling up. A smoking gun would certainly help. If you actually did have that specific thing that's unlikely to be out there or unlikely to be found where someone gave a specific direction and you know that happened. I also agree the economy is not a reason to worry about the relationship. Balance in the Middle East is, who's going to be in control there is. I'm in favor of what we tried to do with Russia and other countries, barring people from coming to the country, having an economic impact. I think we have to see whether we can make the case that the crown prince would be one of those people. The president comes out on Tuesday and you know what you know and he says we can't prove anything, what would your reaction be? I do know what I know. Let's see what the president says on Tuesday. High confidence doesn't mean you actually have what you need if that's the term the CIA is using. I'm not talking about what we heard this week, but what we read in the paper this morning. If that is accurate, it means we don't quite have all the information we would like to have. It would be nice -- if we're going to deal with this relationship which would impact the balance of power in the Middle East. It impacts the balance to Iran which is clearly a bad actor. We need to be absolutely sure we know exactly what we're talking about and not what the first step is, but also what the second and third step that that first step would lead you to really determines. There's been some question about what the president knew and when on the crown prince's role in khashoggi's death. Take a look at this tweet from president Obama's deputy we're faced with the real possibility that trump has had info from his own Intel community that mbs was responsible for murdering a journalist who wrote for the "Washington post" and lied about it and tried to help mbs get past it. Must be investigated. Do you think he knew something before and khashoggi should have been warned? I don't know the specific answer. I do know I know more than Ben Rhodes. I think that's pretty wild speculation. Are you concerned the president has ignored the intelligence in order to protect the relationship? No. Not at all? No. I want to move to the Mueller investigation and about Whitaker. President trump weighed in on Twitter. The inner workings of the Mueller investigation are a total mess. They've found no collusion and have gone absolutely nuts. They are screaming and shouting at people, horribly threatening them to come up with answers they want. They've gone absolutely nuts? Have you seen any evidence of that? I don't know what the president is talking about. I do know it's not news that the president thinks this of the Mueller investigation. Most members of the house and senate have engaged saying Mr. President it would be a huge mistake not letting the Mueller investigation come to a conclusion. We need to get beyond this. We don't need to have this starting again. You have confidence in the Mueller investigation? I do. Let's talk about the acting attorney general, Matt Whitaker. Lindsey graham said on another program this morning I don't know if he's the best choice. What do you think about that? Well, what we really need is a permanent attorney general. We need to move as quickly as we can beyond the acting attorney general to the attorney general who's going to be there for a much longer period of time. We'll see. I don't know Matt Whitaker well. I've known him for sometime. I met him in Iowa when he was U.S. Attorney. On the occasions I've had with him he's been very responsive and has seen that the justice department responded to the things I asked about. In terms of an acting capacity he seems to me to be the person who has the ability to do the acting job. But not a permanent position? Is that what you're saying? I would think not, but the president needs to determine who is going to be permanently at the justice department as quickly as he can. What are you looking for? One of our big challenges is our friends on the other side on the senate have made it so hard to get anybody confirmed to anything. The president is unlikely to make that nomination before the congress reconvenes. If he did, we would be unlikely to do anything with it. We are way beyond the time where you have a hearing and a week later somebody gets confirmed to these jobs, no matter how insignificant they are. This one of course is very significant. Tell me what you're looking for in an attorney general, if not Matt Whitaker. Well, I think what the president should be looking for is someone who can manage the justice department, who understands the impact of that department, hopefully has had some experience working with or in the department before that. As for the Mueller investigation? As for the Mueller investigation, I think the Mueller investigation is going forward. In terms of an attorney general? In terms of an attorney general, the big question here on the Mueller investigation I think is whether the congress has any ability to tell the president who can work in the executive branch. That's a constitutional question. It's different than the question of whether Mueller should be allowed to continue. It's what could you do about. This idea that we would have a debate and have a vote and put a bill on the president's desk that he wouldn't sign, I don't think that's nearly as impactful as members continuing to say Mr. President, we need to get beyond this and you need to let it come to a conclusion. I don't have any reason to believe Matt Whitaker feels differently. Thank you for joining us. You bet. Up next the midterms

This transcript has been automatically generated and may not be 100% accurate.