WATCH: US Capitol Riot Probe Focusing on What Trump Did During Mayhem
For more than three hours, the former president refused entreaties to call off rioters 
Washington — U.S. lawmakers investigating the Jan. 6 riot at the U.S. Capitol last year focused their Thursday night hearing on what former President Donald Trump was doing for more than three hours at the White House as thousands of his supporters rampaged through the Capitol trying to block the certification of Joe Biden's electoral victory. The nine-member House of Representatives committee investigating the mayhem showed a montage of videotaped testimony from key Trump White House aides, and presented live testimony from two more, to support their allegation that Trump watched the insurrection on television and did nothing to stop it for hours. In his opening remarks, Representative Bennie Thompson, a Democrat who is the chairman of the committee, said, "For 187 minutes on January 6, this man [Trump] of unbridled destructive energy could not be moved. Not by his aides, not by his allies, not by the violent chants of rioters, or the desperate pleas of those facing down the mob. He could not be moved." Democratic Representative Elaine Luria, a committee member who led much of the questioning Thursday, told CNN earlier this week that the panel will explore "minute by minute" what Trump was doing for three hours and seven minutes on the afternoon of Jan. 6 — from the end of his speech at a rally urging his supporters to walk to the Capitol and "fight like hell" to finally telling them they should disperse. During her opening statement Thursday, Luria said the evidence shows that Trump "sat in his dining room and watched the attack on television, while his senior-most staff, closest advisers and family members begged him to do what was expected of any American president." Republican committee member Adam Kinzinger, who questioned witnesses, told CBS'  on Sunday, "The president didn't do much but gleefully watch television during this timeframe." Vice chairperson and Representative Liz Cheney, a Republican, swore in two new witnesses — former deputy press secretary Sarah Matthews and former deputy national security adviser Matthew Pottinger, both of whom quit the day of the insurrection in protest of Trump's reaction to the riot. Matthews provided details of what she saw in the White House that day, including whether Trump knew the violence had broken out when he took aim at then-Vice President Mike Pence in a 2:24 p.m. tweet complaining about Pence’s refusal to block certification of Biden’s victory. Trump tweeted: "Mike Pence didn't have the courage to do what should have been done to protect our Country and our Constitution, giving States a chance to certify a corrected set of facts, not the fraudulent or inaccurate ones which they were asked to previously certify. USA demands the truth!" Trump had implored Pence both privately and publicly before the riot to send the election results back to the states he narrowly lost so new electors favoring Trump could replace the official ones favoring Biden. Constitutional experts say that would have been illegal. In the United States, presidents are effectively chosen in separate elections in each of the 50 states, not through the national popular vote. Each state’s number of electoral votes is dependent on its population, with the biggest states holding the most sway. The rioters who stormed the Capitol tried to keep lawmakers from certifying Biden’s eventual 306-232 victory in the Electoral College. Matthews said in a clip from her video deposition, "I remember us saying that that was the last thing that needed to be tweeted at that moment. The situation was already bad. And so, it felt like he was pouring gasoline on the fire by tweeting that." Pottinger told the panel that Trump's tweet prompted him to resign. "I read that tweet and made a decision at that moment to resign," he said in his video deposition. "That's where I knew that I was leaving that day once I read that tweet." Earlier videotaped witnesses at the hearings, including Trump’s daughter Ivanka, a White House adviser, said the president ignored their entreaties to publicly call off the rioters. Trump eventually released a videotaped statement after 4 p.m. asking the rioters to leave the Capitol. In another tweet sent later, he appeared to justify the mob’s actions. “These are the things and events that happen when a sacred landslide election victory is so unceremoniously & viciously stripped away from great patriots who have been badly & unfairly treated for so long,” he wrote. “Go home with love & in peace. Remember this day forever!” Trump, who has strongly suggested he will make another run for the White House in 2024, to this day claims he was cheated out of re-election. He has often derided the January 6 investigative panel, posting a message Tuesday on his social media platform Truth Social that the committee “is a Fraud and a disgrace to America.” Trump has said he would consider pardoning the more than 800 protesters arrested during the rioting if he becomes president again. Thursday night’s public hearing originally was set to be the last, but now committee members say they are continuing to gather information about the riot and could hold new hearings in September and beyond.