Seeking insight into how the violence that erupted at the U.S. Capitol last January was plotted, the House select committee tasked with probing the insurrection subpoenaed various extremist right-wing organizations and their figureheads on Tuesday.

It is the second time this week that the committee has added to an already thick stack of subpoenas sent to individuals entrenched in former President Donald Trump's lies about the 2020 election.

Twenty-four hours ago, Trump stalwarts and conspiracy theorists Roger Stone and Alex Jones were among the recipients of a committee subpoena. On Tuesday, the latest batch from the select commission zeroed in on extremists involved in the attack like Proud Boys International LLC, that group's former chairman Henry "Enrique" Tarrio, the Oath Keepers organization and its president Elmer Stewart Rhodes, and the First Amendment Praetorian, a far-right quasi-paramilitary group that has run security for pro-Trump events in the past. That group's chairman, Robert Patrick Lewis, was also subpoenaed.

Heaps of Proud Boys and Oath Keepers members have been brought up on criminal charges specifically tied to the January 6 attack. In the 11 months since the siege, prosecutors have repeatedly argued that the groups conspired with each other to stop the certification of the 2020 election.

However, neither Tarrio, Rhodes, nor Lewis have been charged with crimes related directly to the activities that occurred on January 6. Tarrio is currently serving a five-month sentence in a D.C. jail for stealing and burning a Black Lives Matter banner last December and possessing two large-capacity firearm magazines when stopped in Washington on January 4.

On Tuesday, Rhodes was identified by the committee as the person referred to in an indictment returned earlier this year by a grand jury involving a January 6 defendant. Rhodes, the committee notes, "describes a conspiracy among at least 18 Oath Keepers in which members of the Oath Keepers planned to move together in coordination and with regular communication to storm the United States Capitol on January 6, 2021."

The Oath Keepers subpoena was hotly anticipated given the group's obvious involvement in breaching the U.S. Capitol. They were seen breaching the building with a military formation and proudly displayed their insignia throughout the day.

Almost two dozen of the organization's leaders have been charged with crimes related to the attack. The Department of Justice has indicated that the group hid firearms at a hotel in Arlington, Virginia.

In court, according to Politico, one Oath Keeper ringleader, Kelly Meggs, "told allies 'this isn't a rally,' which U.S. District Judge Amit Mehta has described as key evidence of the group's intent."

Robert Patrick Lewis, a former U.S. Army staff sergeant who spearheads the 1st Amendment Praetorian, has not been charged with any crimes related to January 6, but his track record of conspiracy theories, propaganda, and actual role in rallies leading up to the Capitol attack has grabbed the committee's interest.

The group posted a list of Trump events that it provided security to online, including several "Stop the Steal" rallies held in Washington, D.C., and Atlanta, Georgia.

"1st Amendment Praetorian provided security to the Million MAGA March on November 14, 2020, including providing protection to Ali Alexander, you described your coordination with Mr. Alexander as 'tight at the hip,'" the subpoena to Lewis states.

Alexander organized the Stop the Steal rally at the Ellipse on January 6 and has also been subpoenaed by the committee.

"You later claimed that you provided security for Lieutenant General Michael Flynn at the 'Jericho March' in Washington, D.C. on December 12, 2020, and have claimed to coordinate closely and regularly with Lt. Gen. Flynn. You have also claimed to coordinate closely with Sidney Powell [Trump's former attorney]," the subpoena notice to Lewis states.

Significantly, Lewis also took to Twitter just two days before the attack on January 6, saying: "There may be some young National Guard captains facing some very, very tough choices in the next 48 hours. Pray with every fiber of your being that their choices are Wise, Just and Fearless."

Lewis was also listed as a speaker on a permit for a rally on January 5 in D.C. In the permit, Lewis noted that 25 fellow members of his organization would serve as "demonstration marshals."

And on the day of the insurrection, just after 2 p.m., Lewis tweeted: "Today is the day the true battles begin."

A day after the attack, Lewis bragged on an independent QAnon conspiracy broadcast known as Patriot Transition Voice that he was "war-gaming" with "constitutional scholars" to keep Trump in office before the Capitol breach. Though the group has a lower profile than the Oath Keepers or Proud Boys, the January 6 Committee has singled them out before. This August, the panel highlighted Lewis and the organization he leads in its request for White House documents from the National Archives.

While the overlap between and among these groups is striking, the critical element presently missing for investigators is proof that it was Trump himself who intended to use the violence overwhelming the Capitol as a means to disrupt Congress's counting of electoral votes. The victory already belonged to President Joe Biden at that time, but the formality is part and parcel of ensuring a peaceful transition of power.

"We believe the individuals and organizations we subpoenaed today have relevant information about how violence erupted at the Capitol and the preparation leading up to this violent attack," committee chairman Bennie Thompson said in a statement Tuesday. "The Select Committee is moving swiftly to uncover the facts of what happened on that day, and we expect every witness to comply with the law and cooperate so we can get answers to the American people."