Cassidy Hutchinson, a special assistant and aide to Trump's chief of staff, Mark Meadows, will testify, a person familiar with the matter told The Associated Press. She has already provided a trove of information to the committee and its investigators and sat for multiple interviews behind closed doors.
The committee on Monday called the unexpected hearing to present "recently obtained evidence and receive witness testimony," according to the announcement. The committee had signaled last week that it wouldn't hold another hearing until July.
When is the hearing scheduled? What might be discussed? Here's what we know:
Who is Cassidy Hutchinson?: Cassidy Hutchinson to testify at Jan. 6 hearing. Who is the former aide to Mark Meadows?
DOJ leaders hold the line: How Justice leaders Rosen, Donoghue and Engel held the line against Trump in the run-up to Jan. 6
What time is the Jan. 6 hearing on Tuesday?
The hearing is scheduled to begin at 1 p.m. EDT.
How to watch the Jan. 6 hearing
USA TODAY will livestream the hearings here on USATODAY.com. The hearings have also been televised on C-SPAN and cable news networks.
What will the hearing focus on?
Details have not been released about the new evidence obtained by the committee. Cassidy Hutchinson, senior aide to former White House Chief of Staff Mark Meadows, will testify, according to Punchbowl News.
Jan. 6 committee evidence: Is the Jan. 6 committee sitting on explosive evidence of Trump's role in the Capitol assault?
Who is Cassidy Hutchinson, Mark Meadows' former aide?
Hutchinson told the committee about White House strategy sessions where Republican House members, which she named, discussed how to reject electors from certain states Joe Biden won in the 2020 election.
Here's what else she told the committee:
Meadows kept communications confidential: She described how Meadows tried to keep his communications confidential. Meadows communicated with the encrypted application Signal, according to court records.
Trump and the chants to hang Pence: Hutchinson also told the panel Meadows told colleagues after watching television coverage Jan. 6 of the riot that Trump spoke approvingly of the chants to hang then-Vice President Mike Pence, according to the New York Times.
The pardon requesters: Hutchinson told the committee, in a deposition released last week, that at least five House Republicans requested a pardon after the Capitol attack, including Reps. Mo Brooks, Matt Gaetz, Andy Biggs, Louie Gohmert and Perry.
Republicans request pardons after Jan. 6: Meet the 5 Republican congressmen who aides say asked Trump for a pardon after the Jan. 6 attack
Threats against Jan. 6 committee members: Jan. 6 committee members are receiving rising threats of violence, GOP Rep. Adam Kinzinger says
What did we learn on Thursday?
Trump was frustrated with what he perceived as the DOJ's unwillingness to investigate his claims of election fraud. Officials shot down his suggestions to appoint a special counsel, meet with his reelection campaign lawyers and file a lawsuit with the Supreme Court.
Trump wanted the DOJ to "lend credibility" to his claims of election fraud and told agency heads to "leave the rest to me and the Republican congressmen," according to evidence.
Trump sought to replace then-acting Attorney General Jeffrey Rosen with Clark, an environmental lawyer. The committee presented a draft letter written by Clark addressed to Georgia legislative leaders which falsely alluded to possible voter fraud in key states.
The committee presented a recorded testimony of Clark invoking his Fifth Amendment right when asked about the draft letters to Georgia officials.
Rep. Scott Perry, R-Pa., sent text messages to Meadows and others to lobby the White House to elevate Clark within DOJ.
DOJ officials threatened to resign en masse if Trump replaced Rosen with Clark.
A roster of GOP lawmakers, including Reps. Mo Brooks of Alabama, Matt Gaetz of Florida and Andy Biggs of Arizona, asked for presidential pardons the day after Jan. 6, 2021, according to aides.
What else happened last week?
Committee members recently interviewed British documentarian Alex Holder, who filmed Trump and his children before and after the attack on the Capitol.
Holder, the British filmmaker who recorded Trump and members of his team around the time of the attack on the Capitol, provided the Jan. 6 committee with footage of Trump, Ivanka Trump and Donald Trump Jr., among others.
Federal authorities searched former DOJ official Jeffrey Clark's home on Wednesday, a day before the committee presented evidence outlining former President Donald Trump's plan to install Clark, who backed his false claims of election fraud, as acting attorney general.
Election workers testify: At Jan. 6 hearing, a spotlight on two election workers who faced down Trump and his allies' demands
Jan. 6 committee hearing schedule: When is the next hearing?
It's unclear when the next hearing is at the moment. Tuesday's hearing was scheduled after Rep. Bennie Thompson, D-Miss., the committee's chair, said last week that hearings were expected to begin again in July.
Poll shows support for charges: Nearly 6 in 10 Americans say Trump should be criminally charged for his role in Jan. 6 riot, ABC poll says
Reach out to Chelsey Cox on Twitter at @therealco.
This article originally appeared on USA TODAY: Cassidy Hutchinson, ex-Meadows aide, will testify at Jan. 6 hearing