SCOTT DETROW, HOST:

Today marks the first of a series of deadlines for federal agencies and social media companies to turn over records to the House Select Committee investigating the January 6 attack on the Capitol. House Intelligence Committee Chairman Adam Schiff, who also sits on the select panel, tells NPR...

ADAM SCHIFF: At the end of the day, we are determined to draft a comprehensive report over everything that led up to January 6 and what happened that day and the aftermath.

DETROW: This as the Capitol preps security for a planned far-right demonstration in support of those charged criminally in the deadly riot. To tell us more, we're joined now by NPR congressional reporter Claudia Grisales.

Hey, Claudia.

CLAUDIA GRISALES, BYLINE: Hey, Scott.

DETROW: So what is important about today for the committee, and what comes next?

GRISALES: Well, as you mentioned, this is the first major mile marker in this panel's efforts to gather a massive trove of documents and build a public record of the days and weeks leading up to the attack. The panel has also ordered telecom firms to preserve phone records, text messages of allies to former President Trump as part of its requests. Schiff also talked about that with me and the interest in gathering these documents. Let's take a listen.

SCHIFF: If anyone who was in communication with the president on that day about the January 6 attacks while they were going on or in conversation with the president in the days leading up to it about January 6 has relevant information, that ought to be made public.

GRISALES: So as you can imagine, there's a long list of individuals of interest who may have had those discussions, including members of Congress such as top House Republican Kevin McCarthy, who said he talked to Trump that day.

DETROW: And a big part of the story has been McCarthy and many House Republicans trying to dismiss this committee by boycotting it. How are they responding now?

GRISALES: So far, some have focused their ire on these preservation orders for phone records. For his part, McCarthy said these companies don't need to comply with these requests, even threatened them - if they do turn them over, they would be in violation of federal law and Republicans would not forget. However, Schiff said, as was seen during the intel panel's investigation into Trump and Russian election interference, that members of Congress have been successfully targeted in probes in the past.

Now, the committee has not made this list of individuals they are targeting public, but these names were attached to letters sent out with these requests. We imagine we'll learn more about them and their roles as this investigation continues. That said, Schiff did not rule out the possibility that subpoenas may be in order for companies who will need the legal grounds to release such documents.

Now, we should note, today's deadline only applies to records for federal agencies tied to the Trump White House communications and efforts to fuel election misinformation through social media companies. So when it comes to telecom companies turning over records, those are not due yet, and that's likely to be a long road ahead.

DETROW: And then there's this thing looming out there. About a week and a half from now, the Capitol could face another big potential security test. Where do plans stand on that?

GRISALES: Yes, a far-right demonstration is planned for Saturday the 18 at the Capitol to support those who were charged in the attack. And Congress is not slated to be in session. However, House Speaker Nancy Pelosi has asked the top Democratic and Republican leaders in each chamber to join her in a security briefing with the Capitol Police Chief Tom Manger on this. Manger and the D.C. Metropolitan Police Chief Robert Contee have both said their agencies are fully prepared and considering new potential security measures. For example, a person familiar with the discussions told me today that Capitol Police are planning to reinstall fencing ahead of the September 18 demonstration.

DETROW: Fences going back up. NPR congressional reporter Claudia Grisales, thank you so much.

GRISALES: Thank you. Transcript provided by NPR, Copyright NPR.