Transcript for 2 National Guard servicemen in DC sent home after links to extremist groups
In the meantime tonight, the capitol on lockdown, with 25,000 National Guard troops on duty, and we learned today that at least 12 guardsmen have now been relieved of duty. What we've learned tonight, and here's our chief justice correspondent Pierre Thomas now. Reporter: Tonight, all bridges leading into the capital shut down. One of the final pieces of a vice-like lockdown ahead of tomorrow's ceremonies. 25,000 national guardsmen, many armed, ringing the capitol. And today, concerns about threats from within the ranks. At least a dozen guardsmen have been removed from the mission. Two sent home after vetting for extremist links found suspicious comments. Any reason that somebody's name is brought to the attention of the command, they're being removed from the line. We'll ask questions later. Reporter: The FBI concerned about lone wolves, and warning law enforcement about qanon conspiracy theorists allegedly discussing plans to dress as national guardsmen. And tonight, the justice department filing the first major conspiracy charges connected to the riot. Thomas Caldwell described in an affadavit that includes video as a commander with the oath keepers militia, accused of organizing this squad of up to ten members for their role in the assault on the capitol. Prosecutors alleging late today that while the capitol attack was under way, Caldwell received a Facebook message telling him to trap members of congress in the tunnels below the capitol and to turn on the gas. Investigators are also using recovered cell phone data, even gps location information, to build their cases against rioters. Overnight, Riley Williams, taken into custody. Authorities are investigating whether she may have stolen a laptop from Nancy Pelosi's office in an effort to sell it to Russian intelligence. And Pierre Thomas with us again tonight. And authorities remain convinced they can keep this inauguration outdoors tomorrow and keep it safe? Reporter: David, authorities are confident, but they're leery about the unknown and they're worried not just about tomorrow, but the days ahead. As many as 6,000 National Guard may stay in the city for up to 30 days after the inauguration, David. All right, Pierre Thomas with us again tonight. Pierre, thank you. Of course, ABC news will provide complete coverage of all of the historic events tomorrow beginning at 7:00 A.M. Eastern, with a special edition of "Good morning America" first thing in the morning and then I'll be joining George and linsey and the entire team all day long, right here on ABC.
This transcript has been automatically generated and may not be 100% accurate.