Hutchinson's testimony offered a number of striking new revelations, including insights into former President Trump's frame of mind as his rally-goers began descending on the Capitol, and anecdotes regarding how he handled anger in the past.
Tuesday's meeting is the sixth public hearing held by the committee. The hearings began on June 9 and have each featured new revelations about the events leading up to the attacks and how Trump and his allies responded.
Here are a few of the biggest allegations from Tuesday's surprise hearing.
Donald Trump Physically Assaulted His Secret Service Agent
In one of the most striking moments of Hutchinson's testimony, she relayed an anecdote she heard from Trump's head of Secret Service, Robert Engel.
Following his fiery speech to supporters on Jan. 6, Trump had expressed an interest in traveling to the Capitol, Hutchinson said, but his security was against the idea.
So Trump, she testified under oath, took matters into his own hands.
Deputy Chief of Staff Tony Ornato explained to Hutchinson how, when Trump got in his presidential limousine following his speech, "he was under the impression that he could still go to the Capitol."
"When [Engel] relayed, 'We are not ... it's not secure,' the president had a very strong, very angry response to that ... Tony described him as being irate," she said.
According to Hutchinson, Engel said that Trump yelled, "I'm the f------ president, take me up to the Capitol now," to which Engel responded, "Sir, we have to go back to the West Wing."
"The president then reached up to grab at the steering wheel," Hutchinson said, recalling what she was told.
When Engel grabbed Trump's arm to tell him not to take over the steering wheel, Hutchinson said Trump then grabbed at Engel's "clavicle," gesturing to her own throat to demonstrate what she had been told.
Jabin Botsford/The Washington Post via Getty; Brandon Bell/Getty Donald Trump, Cassidy Hutchinson
Trump Would Throw Plates of Food at the Wall in Fits of Anger
Elsewhere in her testimony, Hutchinson described other moments of anger for Trump, telling the committee that she once walked in to a room in the White House to see a valet cleaning up after Trump had "thrown his lunch against the wall."
"There was ketchup dripping down the wall," she said, and a shattered porcelain plate on the ground. The valet told her that Trump had grown angry after Attorney General Bill Barr fact-checked his false claims of election fraud in an interview with the Associated Press.
And it wasn't the only time he threw food or utensils, she added, telling the committee the former president was known to "flip tablecloths to let all the contents of the table go off."
White House Lawyers Worried About Getting Charged 'with Every Crime Imaginable'
In the days leading up to the Jan. 6 "Stop the Steal" rally, White House counsel tried to persuade the former president not to use incendiary rhetoric in his speech.
But the lawyers were seemingly even more concerned by another prospect — that Trump himself would march or drive to the U.S. Capitol building, as he had proposed.
Hutchinson testified that White House lawyer Pat Cipollone told her on the morning of Jan. 6 not to let Trump go to the Capitol, otherwise "we're going to get charged with every crime imaginable," including obstruction of justice or defrauding the electoral count.
"Mr. Cipollone said something to the effect of, 'Please make sure we don't go up to the Capitol, Cassidy,'" she testified. "'Keep in touch with me. We're going to get charged with every crime imaginable if we make that movement happen.'"
Trump Didn't Care That Rally Attendees Had Weapons Because He Wanted a Larger Crowd Size
At the rally held prior to the attempted insurrection, Trump gave a speech to supporters imploring them to "march to the Capitol" and "fight" to overturn the election results. The committee played police scanner recordings that showed that some attendees at the rally were seen carrying Glock handguns and automatic weapons.
She said the former president was told that morning that many of the attendees had weapons and could not get closer to the stage due to magnetometers being used by security at the event.
But Trump was undeterred, she testified.
In a text message exchange shown at the hearing, she described Trump as "f------ furious" due to the crowd size — "because he wanted the arena to be maxed out at capacity," she said.
Hutchinson further testified that she overhead Trump say, "I don't f------ care that they have weapons. They aren't here to hurt me … Take the f------ [magnetometers] away."
Mark Meadows and Rudy Giuliani Requested Pardons
Hutchinson said that both her own former boss, Meadows, and Trump attorney Rudy Giuliani sought presidential pardons following the events of Jan. 6.
Meadows — who helped spread the former president's baseless fears of voter fraud — was last year held in contempt of Congress for refusing to testify to investigators looking into the Jan. 6 insurrection at the Capitol.
Last week, the committee aired video footage of Hutchinson's earlier deposition, in which she testified that several Republican members of Congress sought a blanket pardon for their involvement in the former president's attempts to overturn his defeat.
Hutchinson said that Rep. Matt Gaetz — who is currently the subject of a grand jury investigation into whether he had a sexual relationship with a 17-year-old and paid her to travel with him — had been seeking a pardon since early December, one month before the Jan. 6 Capitol riots.
"Mr. Gaetz was personally pushing for a pardon, and he was doing so since early December," Hutchinson alleged, adding: "I'm not sure why Mr. Gaetz had reached out to me to ask if he could have a meeting with Mr. Meadows about receiving a presidential pardon."
In the pre-recorded testimony that aired last week, Hutchinson also testified that Reps. Andy Biggs, Louie Gohmert and Scott Perry had contacted the White House to inquire about securing pardons.