US Secret Service Director Kimberly Cheatle faced off Monday with angry lawmakers from both parties, who grilled her over the stunning security failures that led to the recent assassination attempt against Donald Trump.

Cheatle acknowledged that there were “significant” problems at Trump’s rally in Butler, Pennsylvania, on July 13, where the former president was shot in the ear, and she didn’t downplay the historical and political significance of the event.

Before Trump took the stage at the rally, the director said, the Secret Service had been notified “between two and five times” that there was a suspicious person in the area.

Yet one by one, as members of the House Oversight Committee tried to pry loose new information about the security breakdown and what is being done to ensure it never happens again, Cheatle repeatedly stonewalled lawmakers’ efforts to get answers and pointed to the ongoing FBI investigation.

The director also remained defiant in the face of bipartisan calls for her immediate resignation, including from Rep. Jamie Raskin, the top Democrat on the Oversight Committee.

Here are key takeaways from Monday’s hearing:

Cheatle admits ‘colossal failure,’ but won’t resign

Right off the bat, Cheatle acknowledged that the Trump assassination attempt was “the most significant operational failure at the Secret Service in decades.” She later said it was the worst moment for the agency since the unsuccessful assassination attempt targeting President Ronald Reagan in 1981.

But even with that historic failure under her watch, Cheatle was insistent that she won’t step down.

A bipartisan chorus of lawmakers called for her to resign her post. The criticism was sharper from Republicans, but Democrats also prodded Cheatle to let go. Democratic Rep. Ro Khanna pointed out that the Secret Service director who ran the agency when Reagan was shot eventually resigned from his post. (That director resigned eight months following the assassination attempt.)

“Do you really, genuinely, in your heart, believe that you being in this role is what’s right for America at this moment?” Khanna asked.

“I will remain on, and be responsible to the agency, to this committee, to the former president, and to the American public,” Cheatle replied, touting her nearly 30-year record working up the agency’s ranks.

Earlier in the hearing, she said, “I think I am the best person to lead the Secret Service at this time.”

Under tough questioning from GOP Rep. Nancy Mace, Cheatle conceded that the incident was a “colossal failure.” Mace ripped into Cheatle, telling her, “you’re full of sh*t today” because of her uncooperative posture throughout the hearing.

No resources withheld from Trump rally, Cheatle says

Rep. James Comer, the GOP chairman of the committee, pressed Cheatle over whether, prior to the shooting, Trump had been given all the security he requested.

Cheatle said that “for the event on July 13, the assets that were requested for that day were given.”

CNN previously reported that there were previous events where the Secret Service denied requests from Trump’s security detail, though the agency instead, in some instances, provided other security measures from local law enforcement.

GOP Rep. Jim Jordan also pressed Cheatle on whether she lied to the nation because – the morning after the shooting – the top spokesperson for the Secret Service forcefully denied allegations that the agency had rejected any requests for additional security.

“For the event in Butler, there were no requests that were denied,” Cheatle said.

“Well, maybe they got tired of asking,” Jordan said.

Cheatle’s careful answers – and non-answers

Cheatle frustrated lawmakers Monday as she walked a tightrope with her testimony, giving carefully worded answers and plenty of non-answers to tough questions.

The top Republican and Democrat on the House Oversight Committee peppered Cheatle with some of the biggest questions that are still unresolved: Were any Secret Service agents on the roof where gunman Thomas Matthew Crooks fired shots at Trump? Did Crooks fly a drone over the area before the rally began? Why wasn’t he stopped when people spotted him on the roof with a rifle?

In response to these questions, and more, Cheatle pivoted away and didn’t directly answer. Regarding Crooks’ possible drone, she confirmed that this is what the FBI told her, but said it was still being probed.

“We are just nine days out from this incident, and there’s still an ongoing investigation,” Cheatle said on a few occasions throughout the hearing. She also said, “I’m not going to get into specifics of that day.”

Cheatle revealed some details – like the fact that she has spoken with the counter-sniper who killed Crooks and that her agency didn’t reject any requests from Trump’s campaign for additional security at the specific rally in Butler.

“We need to have confidence that if the FBI’s leading this investigation, that they’re leading a credible investigation,” Comer told Cheatle directly. “Because there’s some of us sitting up here that don’t have a lot of confidence in the FBI.”

Democratic Rep. Shontel Brown later told Cheatle, “You’re not making this easy for us,” after a series of non-answers. Other lawmakers from both parties said they thought Cheatle was less forthcoming and candid in her sworn testimony at Monday’s hearing than she was in her recent TV interviews.

How was Trump allowed on stage?

Before Trump took the stage on July 13, the Secret Service had been notified “between two and five times” that there was a suspicious person in the area, Cheatle said.

She said the agency was still looking into the apparent communication breakdown – which led to Trump going onstage even amid these reports of a suspicious person, and as rallygoers saw Crooks with a gun in the immediate moments before the shots rang out.

“I have to assume that they did not know that there was a threat when they brought the president out on the stage,” Cheatle said.

However, there’s “a distinction between suspicious behavior and a threat,” Cheatle explained, “and at the time that this individual was identified, they were displaying suspicious behavior,” and those early reports about Crooks didn’t identify him as an active threat.

When asked by GOP Rep. Russell Fry when exactly Crooks was identified as a threat, Cheatle said it was mere seconds before he started shooting at the former president.

“It’s approximately five minutes to where individuals relayed that there was an (issue) being worked at the three o’clock of the former president,” the lawmaker from South Carolina said, referring to Crooks’ location from Trump’s perspective. “But it was not phrased as a threat. It was just that something was being worked on. When did he transform from suspicion to threat?”

“I believe that it was seconds before the gunfire started,” Cheatle said.

Democrats pivot to gun control

In his opening statement, Raskin homed in on the gun violence that has plagued the US and labeled the Trump assassination attempt as a “mass shooting.”

“Mr. (Corey) Comperatore, President Trump and the other rally attendees wounded in Butler are now members of a club no one wants to belong to — the thousands of people who have fallen victim to mass shootings,” Raskin said, as an aide held up a poster listing some of the recent mass shootings in the US.

Some Democrats on the committee pointed out that Crooks used an AR-15-style weapon, which many Democrats have been trying to ban or at least restrict for people under 21, like Crooks.

Rep. Gerry Connolly asked whether Americans having more guns makes Cheatle’s job “easier or harder.”

“The job of the Secret Service is difficult every day,” Cheatle said, before Connolly cut her off, decried the proliferation of assault-style rifles, and chided the Secret Service director for “evading” the gun issue.

Cheatle defends staff after smears target female agents

Cheatle indirectly responded to allegations circling around right-wing media outlets and lawmakers that female agents were in part to blame for security failures at the Trump rally.

Female agents who were part of Trump’s Secret Service detail were photographed shielding the former president after the failed assassination attempt. Some on the right have claimed that the women couldn’t properly protect Trump. (The Trump family has pushed back directly on that claim.)

Asked by a Republican member about her efforts to “change the makeup of the Secret Service” because there was “too high a percentage are men,” Cheatle said she hires only “the best and brightest.”

“I am hiring the best qualified candidates that put in an application that want to work for our great organization,” she responded.

This story has been updated with additional developments.