Members of right-wing militia groups and other supporters of former United States president Donald Trump staged the 6 January 2021 assault on the US Capitol after a tweet from the former president seen as a "call to arms," politicians investigating the riot said on Tuesday.
The House select committee, made up of seven Democrats and two Republicans, is trying to determine whether Mr Trump or his associates had a role in planning or encouraging the violent insurrection and has subpoenaed numerous advisers and aides to the former president.
During its seventh televised public hearing, it examined the impact of a tweet that Mr Trump sent on 19 December 2020 urging his supporters to descend on Washington DC on 6 January for a "big protest", saying: "be there, be wild".
The tweet was sent a little more than an hour after Mr Trump met at the White House with his lawyer Rudy Giuliani, former general Mike Flynn, and Sidney Powell, another lawyer, for a strategy meeting that one aide described as "unhinged."
Committee member Jamie Raskin said Mr Trump's "1.42 am tweet electrified and galvanised his supporters, especially the dangerous extremists in the Oath Keepers, the Proud Boys and other racist and white nationalist groups spoiling for a fight against the government."
Members of the Proud Boys and the Oath Keepers stormed Congress on 6 January along with thousands of other Trump loyalists in an attempt to block certification of Democrat Joe Biden's presidential election victory, which Mr Trump falsely claims was marred by fraud.
Representative Stephanie Murphy, another committee member, said the tweet "served as a call to action, and in some cases as a call to arms, for many of President Trump's most loyal supporters."
The committee said two of Mr Trump's closest backers, Mr Flynn and political consultant Roger Stone, had connections to the Oath Keepers.
The riot was planned by Donald Trump, committee says
The committee also said the march to the Capitol was planned in advance but that Mr Trump decided not to announce it until the speech he made to supporters on the morning of 6 January near the White House.
"The evidence confirms that this was not a spontaneous call to action, but rather was a deliberate strategy decided upon in advance by the president," Mr Murphy said.
Cassidy Hutchinson, an aide to Mr Trump's chief of staff Mark Meadows, testified at a previous hearing that the president had intended to go to the Capitol himself but was prevented from doing so by secret service agents.
It played the first videotaped excerpts on Tuesday from closed-door testimony last week by former White House counsel Pat Cipollone.
In his testimony, Mr Cipollone said he agreed there was no evidence of significant election fraud and that Mr Trump should have conceded to Mr Biden.
The committee also heard from two witnesses, Jason Van Tatenhove, a former spokesman for the Oath Keepers, and Stephen Ayres, an Ohio man who joined the mob storming the Capitol.
Mr Van Tatenhove said the Oath Keepers were a "dangerous organisation" who believed their allegiance to Mr Trump would give them "legitimacy" as a paramilitary outfit.
Mr Ayres told the committee that he came to Washington because "the president got everybody riled up," but that he no longer believed his claims that the election was "stolen."
White House staffers clashed with outside advisers
The committee detailed a "surprise visit" to the White House the night of 18 December 2020 that lasted for more than six hours.
It brought together outside advisers ranging from personal lawyer Rudy Giuliani to disgraced former national security adviser Michael Flynn, and Sidney Powell, a former federal prosecutor who fought to overturn the election on false claims of election fraud.
They presented a draft "executive order" calling for the US military to seize states' voting machines.
White House counsel Pat Cipollone testified he thought that was a "terrible idea."
What followed was several hours of screaming and insults that ranged from the Oval Office to Mr Trump's private quarters, participants testified.
"It was not a casual meeting. At times there were people shouting at each other, throwing insults at each other," said Derek Lyons, former White House staff secretary.
Mr Giuliani said he accused White House staffers of not fighting for Trump's interests.
"You guys are not tough enough. Or maybe I put it another way. You're a bunch of pussies, excuse the expression. I'm almost certain the word was used," he said.
At one point, Mr Trump offered to give Mr Powell a job as a special counsel with a security clearance, participants testified.
It was past midnight when the meeting ended, the witnesses said.
Accusations of witness tampering
Representative Liz Cheney, vice chair of the House committee investigating the attack on Congress, said Mr Trump had recently attempted to contact a committee witness, raising concerns the former president might be illegally trying to influence testimony.
Ms Cheney, a Republican, said the witness did not take the call from Mr Trump and informed their lawyer.
"Their lawyer alerted us. And this committee has supplied that information to the Department of Justice," she said.
"Let me say one more time: We will take any effort to influence witness testimony very seriously."
Liz Cheney (centre) is one of two Republicans on the House select committee investigating the 6 January 2021 US Capitol riot. Source: SIPA USA / Sipa USA/Sipa USA
Ms Cheney said in a television interview broadcast last Thursday that the panel may make a criminal referral to the Justice Department recommending that anybody who tried to influence testimony be prosecuted.
The witness-tampering issue emerged at the committee's hearing a week ago, when Ms Cheney disclosed that some witnesses reported receiving veiled threats from Trump allies to do "the right thing."
Former US official admits he 'helped plan coups'
Former US national security adviser John Bolton meanwhile admitted on Tuesday that he has helped plan coups in other countries, but argued that the 6 January riot fell short of such efforts.
The attack on the US Capitol was the result of then-president Donald Trump "just stumbling around from one idea to another," Mr Bolton told CNN's Jake Tapper.
"As somebody who has helped plan coups d'etat, not here, but, you know, other places, it takes a lot of work," he said.
The 73-year-old — who served as Mr Trump's national security adviser from 2018 to 2019 — did not specify which governments he had helped to overthrow, but while in his post, he advocated for US military intervention in Venezuela.
Mr Bolton said 6 January 2021 was "not an attack on our democracy. It's Donald Trump looking out for Donald Trump. It's a once in a lifetime occurrence".
"Ultimately, he did unleash the rioters at the Capitol. As to that, there's no doubt. But not to overthrow the Constitution, to buy more time, to throw the matter back to the states, to try and redo the issue," he added.
