ARI SHAPIRO, HOST:

During the presidential campaign, unfounded conspiracy theories regularly made their way from the fringes into mainstream news reports. That problem has not gone away. Last July, a 27-year-old staffer for the Democratic National Committee was shot to death here in Washington. D.C. police say it was a botched robbery.

That has not stopped a runaway conspiracy theory that Seth Rich's death was an assassination, that Rich gave DNC emails to WikiLeaks and was killed to cover it up. The outlets pushing this narrative without evidence include Breitbart, Rush Limbaugh and Fox News, where former House Speaker Newt Gingrich spoke about it yesterday morning.

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NEWT GINGRICH: And what does that tell you about what was going on? Because it turns out it wasn't the Russians. It was this young guy who I suspect was disgusted by the corruption of the Democratic National Committee. He's been killed, and apparently nothing serious has been done to investigate his murder.

SHAPIRO: Washington Post reporter Dave Weigel has been covering this story and joins us now. Hi, Dave.

DAVID WEIGEL: Hi, good to be here.

SHAPIRO: Can we just start with a simple fact check of Gingrich's remark that nothing serious has been done to investigate Rich's murder? Is that true?

WEIGEL: That's not true. Police have investigated this, and unfortunately it is one of the many unsolved murders in D.C. right now. It's one of the many unsolved crimes in the neighborhood of Bloomingdale.

SHAPIRO: You've mapped out how this story moved from the fringes to the mainstream. It's a complicated journey. But in a nutshell, how did this happen?

WEIGEL: Well, it really began as soon as Rich was killed. There were questions on the Internet. And what pushed it into the next level was Julian Assange of WikiLeaks doing a very meandering interview with a Dutch TV station where he, to paraphrase him, said our sources take precautions. For example, there's this man Seth Rich in D.C. who was killed. The interviewer pressed if that meant Seth Rich was a source. Assange would not say yes. And that is what Assange has done since then.

What happened over the last week is that first FOX 5, a local Fox affiliate in D.C., said it had new information on the case that literally was based on one interview with an outside investigator who recanted his story within 48 hours. That did not stop Sean Hannity on Fox and then Newt Gingrich later on Fox from furthering this. And it did not stop, I think, one entity we haven't mentioned yet, which is most intriguing, the Russian Embassy of the United Kingdom tweeting about this.

SHAPIRO: And we should say Russia has an interest in this because they have been blamed for the DNC hack. And if they can say that it was somehow this conspiracy theory linked to Seth Rich that might remove some pressure from them.

WEIGEL: Yes, exactly. I've covered a lot of conspiracy theories, and the commonality is that people getting deeper and deeper into them ignore or forget the facts that would complicate the simple storyline.

SHAPIRO: You know, Dave, in the larger conversation about fake news, it seems that one message is buyer beware. Don't trust fringe outlets. Don't trust unreliable individuals. But when you have the former speaker of the House on Fox News, that's not the fringe. What are you supposed to do as a news consumer, I mean?

WEIGEL: Well, it's not just that. I think there is an effort not just to run cliquey news for people who want to believe in conspiracy theories but to sow a lot of confusion about what can be trusted in the rest of the press. The strangeness of what's happening now is that the president is under immense fire for the Russia connection. And a lot of these stories are being pushed as a kind of get-out-of-jail-free card. If we can sow enough confusion that maybe all the hacking was not Russians, then we can save the president from this story.

So you're seeing, I think, an elevation of how fake news works and also its limits. And unfortunately, the limits are not enough to protect this family who lost a son and are deeply distraught to watch his memory be tarnished every single day.

SHAPIRO: That's Dave Weigel of The Washington Post. Thank you very much.

WEIGEL: Thank you.

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