What will probably be the final public hearing of the House committee investigating the Jan. 6, 2021 attack on the U.S. Capitol is expected to highlight newly obtained Secret Service records showing how President Donald Trump was repeatedly alerted to brewing violence that day, and that he still sought to stoke the conflict, according to three people briefed on the records.

The committee plans to share in Thursday's hearing new video footage and internal Secret Service emails that appear to corroborate parts of the most startling inside accounts of that day, said the people briefed, who spoke on the condition of anonymity to discuss sensitive internal records. Former White House aide Cassidy Hutchinson testified in June that Trump was briefed on Jan. 6 that some of his supporters were armed for battle, demanded they be allowed into his rally and insisted on leading them on their march to the Capitol.

Surveillance footage the committee plans to share was taken near the Ellipse that morning before Trump's speech and shows throngs of his supporters clustered just outside the corralled area for his "Stop the Steal" rally. Secret Service officers screened those entering who sought to get closer to the stage. Law enforcement officials who were monitoring video that morning spotted Trump supporters with plastic shields, bulletproof vests and other paramilitary gear, and some in the Secret Service concluded they stayed outside the rally area to avoid having their weapons confiscated, according to people familiar with the new records.

Other internal emails likely to be revealed at the hearing further buttress accounts about staff members warning Trump about the risk and then the reality of violence that day, as he continued to press nervous Secret Service agents to take him to the Capitol to join his supporters marching there, the three people said. After being alerted to violence erupting at the Capitol when he returned to the White House, Trump tweeted criticism of Vice President Mike Pence for not blocking the certification of the election, whipping up supporters who had already trampled over security barricades and were battling police to break into the halls of Congress.

The newly obtained Secret Service records are just part of a larger hearing in which the committee hopes to summarize and remind the American public of all the ways Trump is said to have played a central role in fomenting a violent insurrection at the Capitol, one of the most brutal attacks on democracy in U.S. history, according to multiple people briefed on the evidence and committee plan. While the committee's previous hearings took center stage over several weeks this summer, the committee is trying to revive interest in its probe and deliver what it has privately called its "closing arguments" about past and ongoing threats to democracy as voters prepare to cast ballots next month in the midterm elections.

The hearing aims to highlight new evidence gathered by investigators that corroborates the committee's key findings about Trump and the Jan. 6 insurrection, according to the people briefed: that he sought to rile up his supporters to help block the certification of Joe Biden's electoral victory; used his bully pulpit to encourage a fiery showdown at the Capitol; and then refused to budge to help rescue thousands of lawmakers, staff members and police officers on Capitol Hill who were either fleeing or fighting for their lives that afternoon.

It's unclear, however, if the new material will shed any light on a particularly dramatic part of Hutchinson's testimony, in which she recounted a senior Secret Service official telling her that Trump had erupted in anger and lunged at the lead security agent in his motorcade when told he could not go to the Capitol.

One email the committee has obtained highlights the level of alarm inside Secret Service headquarters on Jan. 6 about the possibility that Trump would get his wish to head to the Capitol — and join a melee in progress.

By 1 p.m. Eastern time that day, according to police testimony, hand-to-hand combat between protesters and officers was breaking out on the steps and platforms immediately outside the Capitol. The Secret Service had just then offered to send reinforcements to help an overwhelmed U.S. Capitol Police force, according to texts and testimony from then-Capitol Police Chief Steven Sund.

The new correspondence obtained by the committee shows that while Trump was still speaking to his supporters and announcing he was going to the Capitol, Secret Service personnel in charge of transportation and field operations scrambled to try to secure a safe motorcade route for the president and his entourage, two people briefed on the records said. The Secret Service staff members sought Washington, D.C., police help to block intersections. But with tens of thousands of protesters in downtown Washington, and D.C. police being dispatched to help Capitol Police with protesters breaking through barricades, D.C. police declined the Secret Service's request.

About 1:10 p.m., Trump had left the Ellipse in his motorcade after finishing his speech, and demanded to go to the Capitol. Trump's detail leader, Bobby Engel, riding with Trump in his sport utility vehicle, told an enraged Trump that they were heading back to the White House and it was not safe to take him to the Capitol, the Washington Post previously reported.

"We don't have the assets," Engel told Trump of the inability to secure safe passage for his motorcade, according to a Secret Service official briefed on Engel's account. By about 1:20 p.m., Trump was back at the White House.

One of the committee's newly obtained documents shows that sometime between 1:30 and 2 p.m., a senior Secret Service supervisor for protective operations emailed Engel with an urgent update and seeking to know if Trump's plan to go to the Capitol was successfully quashed. It came after a tumultuous hour for the Secret Service detail, which had effectively ignored a command from the president.

Even with Trump back at the White House, Secret Service headquarters wanted to be sure the president was staying put. The supervisor, Ron Rowe, warned Engel that the situation was rapidly devolving at the Capitol and sought Engel's confirmation he was not considering taking Trump there, according to a senior law enforcement official familiar with the records turned over to the committee. Rowe urged Engel to call him.

Rowe declined to comment, but Secret Service spokesman Anthony Guglielmi said Rowe's email reflected the larger agency's position: Trump's idea of going to the Capitol was a non-starter.

In other internal emails, agents relayed reports that Trump was angry about being told he couldn't go to the Capitol.

Some of the information, the people briefed said, calls into question the previous testimony of Engel and Anthony Ornato, then a Secret Service leader who was serving in an unprecedented political role of White House deputy chief of staff. Both men told the committee in closed-door depositions that they could not recall certain events relayed by other witnesses, including Trump's demand that the Secret Service let armed people into his rally.

After Hutchinson testified that Ornato told her that Trump had lunged at Engel inside the sport utility vehicle they were traveling in, anonymous Secret Service sources said that Engel and Ornato disputed any altercation occurred and were prepared to say so under oath. The committee has not yet re-interviewed the two men, as lawmakers sifted through the additional trove of Secret Service records. Ornato and Engel, through a Secret Service spokesman, declined to comment.

The vast trove of records turned over to the Jan. 6 committee is the result of an ironic twist of events, according to the people briefed on the documents. The same Secret Service that permanently deleted agents' texts from Jan. 6 and the surrounding days amid congressional requests last year has now provided to the committee this large volume of internal communications from the same time period. Voluntarily, the agency has turned over every record it kept of logistical planning, security concerns and private discussions related to the scheduled protests and president's movements.

This extensive sharing of records — more than 1 million pages' worth and many which the committee did not specifically request — followed a period when the Secret Service came under fire for executing an agencywide destruction of all texts exchanged from agents phones in that key period. Federal regulations mandate the preservation of government records, and the Secret Service's deletion of these records prompted a federal investigation into the failure to do so. The texts were wiped from agents' phones as part of a Secret Service-wide update of employees phones that began in January 2021. Secret Service officials have said the mass deletion of reams of potential evidence was unintentional, and the agency's telephone provider has concluded those texts are now impossible to recover.

The committee had considered sharing a portion of its videotaped interview with Ornato at a previous hearing and it's unclear if lawmakers will do so Thursday. In one portion of his interview, according to two people briefed on his account, Ornato described briefing White House Chief of Staff Mark Meadows the afternoon of Jan. 6 about detailed reports of violence breaking out at the Capitol, as well as police officers being transported to a hospital. The committee learned from other witnesses that Meadows then briefed Trump.

The hearing could build out the evidence that Trump took steps to ratchet up the conflict at the Capitol, despite being warned of escalating violence. Lawmakers on the committee have grown particularly suspicious about the agency's transparency with congressional investigators as they've struggled to obtain some information they requested over a year ago.

The committee's hearing Thursday, probably its final one before the release of its report, will also illuminate how associates of Trump — including chief strategist Stephen K. Bannon and Roger Stone, a longtime friend and onetime adviser — planned on declaring victory regardless of the outcome of the 2020 presidential election, the Post previously reported. The House select committee intends to show video footage of Stone recorded by Danish filmmakers during the weeks before the Jan. 6 violence.

Another portion of this week's hearing is expected to focus on the continuing threat of domestic extremism and political violence spawned by efforts to overturn the 2020 election, according to a person familiar with the matter.

The committee has continued interviewing witnesses in the lead-up to the final hearing, and it interviewed Virginia "Ginni" Thomas, the conservative activist and wife of Supreme Court Justice Clarence Thomas, last month. It's unclear whether the committee will use any of Thomas's interview, which was only transcribed and not videotaped or recorded, Rep. Zoe Lofgren (D-Calif.) said recently in an interview on MSNBC.