WASHINGTON (NewsNation) — In a single afternoon, 25-year-old Cassidy Hutchinson went from a former White House staffer to a high-profile witness in the government’s probe into the Jan. 6 insurrection at the Capitol.

Hutchinson gave two hours of testimony on national television that cast former President Donald Trump as enraged by efforts to keep his armed supporters from attending his speech before many marched to the Capitol and her boss at the time, chief of staff Mark Meadows, as unwilling to confront Trump and staring at his cellphone during key moments.

But who is Hutchinson?

Hutchinson is from Pennington, New Jersey. She attended Christopher Newport University, where she has said in the past she was a first-generation college student. While in college, she interned for House Republican Whip Rep. Steve Scalise and Sen. Ted Cruz.

“I attended numerous events hosted by the president, such as signing ceremonies, celebrations and presidential announcements, and frequently watched Marine One depart the South Lawn from my office window,” Hutchinson said in a 2018 article on the university’s website.

She described having been “brought to tears” when she received an email telling her she’d been accepted to a White House internship program.

“My small contribution to the quest to maintain American prosperity and excellence is a memory I will hold as one of the honors of my life,” she said in part.

She joined the White House shortly after graduation, becoming a staff assistant for the White House’s legislative affairs office. She later was promoted to become Meadows’ aide.

Although a junior staffer, Hutchinson was privy to sensitive matters within the White House. Her office was outside of Meadow’s office, which is directly down the hall from the Oval Office. Trump denied knowing Hutchinson, pumping out harsh attacks on Truth Social, the website he created after Twitter banned him following the insurrection.

“I hardly know who this person, Cassidy Hutchinson, is, other than I heard very negative things about her (a total phony and ‘leaker’),” he wrote.

Hutchinson said she was close enough to Trump at one point to hear him demand that attendees not be screened so that they could fill the crowd, saying, “I don’t effing care that they have weapons. They’re not here to hurt me.”

Hutchinson showed her familiarity with better-known officials in the White House, referring at times to Meadows, security official Tony Ornato, and national security adviser Robert O’Brien by their first names. Meadows, in turn, called her “Cass,” in her retelling of one story.

Several high-profile Republicans said Tuesday that Hutchinson was known to be close to Meadows and often accompanied him in meetings. The committee early in her testimony showed photos of her with Trump and other top officials.

The Associated Press contributed to this report.