Prime-time Jan. 6 hearing to focus on Trump's riot response, with new testimony and evidence

The House select committee investigating the Jan. 6, 2021, attack on the U.S. Capitol will hold its eighth hearing on Thursday -- and its second in prime time -- starting at 8 p.m. ET.

Committee aides say the session will zero-in on then-President Donald Trump's response to the insurrection by a pro-Trump mob, specifically the 187 minutes when they say he took no action to stop the attack between his speech at the Ellipse near the White House earlier that day and his public statement telling rioters to go home.

On Thursday morning, Rep. Adam Kinzinger, R-Illinois, tweeted out snippets of depositions previewing testimony in which multiple former White House officials -- press secretary Kayleigh McEnany, Ret. Lt. Gen. Keith Kellogg, then-national security adviser to Vice President Mike Pence, Trump's former executive assistant Molly Michael and White House counsel Pat Cipollone -- recall Trump in the dining room off the Oval Office watching television as the riot at the Capitol unfolded.

The final clip is Cipollone saying the violence at the Capitol was visible on the screen.

ABC News reported the day of Jan. 6, Trump was in the private dining room watching television and not taking any action to stop the violence.

Later, Kinzinger told ABC Congressional Correspondent Rachel Scott, "it's obvious the president was derelict in his duty, but for all the details you have to watch."

The panel will also discuss what occurred on the remainder of Jan. 6, including a tweet Trump sent around 6 p.m., and the fallout on Jan. 7, 2021.

Trump's tweet -- shortly before he was permanently banned from Twitter, read: "These are the things and events that happen when a sacred landslide election victory is so unceremoniously & stripped away from great patriots who have been badly & unfairly treated for so long. Go home with love & in peace. Remember this day forever!"

Aides also emphasized, without providing details, that there would be new evidence presented Thursday and told reporters that there was "no reason to think" this will be the committee's final hearing, though it is expected to be the last session in the near future.

Two former Trump White House aides are expected to testify, sources previously confirmed to ABC News: former deputy press secretary Sarah Matthews and Matthew Pottinger, who was a member of the National Security Council.

Both Matthews and Pottinger quit on Jan. 6.

ABC News has also learned the committee has outtakes of Trump's pre-recorded message delivered on Jan. 7, where he condemned the attack on the Capitol and pledged a "seamless transition of power." But the outtakes tell a different story -- showing a president struggling to say the election was over and to condemn the rioters, sources familiar with their contents said.

The sources said the committee may show at least some of the outtakes during Thursday's hearing but cautioned that plans to do so could change.

Committee aides -- previewing the hearing in very broad terms -- have said they will show testimony from individuals who spoke to Trump and from those in the West Wing who were aware of what Trump, his staff and his family were doing on Jan. 6.

"What we'll get into tomorrow is what happened when that speech ended and President Trump, against his wishes, was returned to the White House," one aide said Wednesday.

"We're going to demonstrate sort of who was talking to him and what they were urging him to do in that time period," the aide continued. "We're going to talk about when he was made aware of what was going on at the Capitol."

Cassidy Hutchinson, formerly a top aide to Trump's last chief of staff, Mark Meadows, previously testified to the committee about a conversation she had with members of Trump's security detail after the rally at the Ellipse on Jan. 6.

Hutchinson said Tony Ornato, the head of the president's security team, told her that Trump lunged toward his driver in the presidential SUV and tried to grab the steering wheel in a push to be taken to the Capitol with his supporters.

"Tony described him as being irate," Hutchinson testified. (The Secret Service subsequently said it will respond on the record to Hutchinson's account.)

Rep. Bennie Thompson, D-Miss., will be chairing Thursday's hearing remotely as he's recovering from COVID-19. Thompson announced on Monday that he tested positive for the virus and would be isolating for several days, per federal guidelines.

A spokesperson for the committee confirmed the hearing would go on as planned despite Thompson's diagnosis, noting the panel was wishing him a "speedy recovery."

Kinzinger and Rep. Elaine Luria, D-Va., will lead the hearing.

Lawmakers on the committee are also dealing with a revelation about Secret Service records as it relates to Jan. 6.

A government watchdog previously requested messages sent and received by Secret Service personnel around the time of the attack, but a spokesperson for the agency acknowledged last week that text messages from last Jan. 5 and Jan. 6 were deleted after being sought by the Department of Homeland Security's inspector general.

The agency maintained that the deletion occurred during a device-replacement program and was not "malicious."

The House committee subpoenaed the Secret Service for the records on Friday and the National Archives and Records Administration asked the agency to account for the lost texts.

The service has only provided a single text exchange to the DHS inspector general, according to an agency letter to the House Jan. 6 committee and obtained by ABC News.

Rep. Pete Aguilar, D-Calif., said the committee was working to get to the bottom of the situation.

"We continue to work through these issues but clearly that's not enough," Aguilar told ABC News.

"There's a lot more questions to answer, but we have the responsibility to tell the truth and chase the facts and that's exactly what we plan to do in this regard, as well as our general oversight over the executive department," Aguilar added.

ABC News' Rachel Scott contributed to this report.