“This incident does not define us,” Cheatle told staff. “I do not want my calls for resignation to be a distraction from the great work each and every one of you do towards our vital mission.”

The attack, in which a gunman opened fire with an AR-15 rifle from an apparently unsecured roof at a Trump presidential campaign rally July 13, was the first against a U.S. leader on the elite protective agency’s watch in more than 40 years. Cheatle, a veteran Secret Service agent, had called the security failure unacceptable and acknowledged that “the buck stops with me.”

She initially had said she would not resign and would cooperate with investigations into the shooting.

But during a House Oversight Committee hearing Monday, Cheatle faced withering scorn from Republicans and Democrats alike. Lawmakers took turns criticizing her for declining to answer detailed questions about what went wrong at the Trump rally.

After Cheatle’s resignation, Oversight Committee Chairman James Comer (R-Ky.) took credit for pushing her out and pledged “more accountability to come.”

“Egregious security failures leading up to and at the Butler, Pennsylvania campaign rally resulted in the assassination attempt of President Trump, the murder of an innocent victim, and harm to others in the crowd,” Comer said in a statement. “We will continue our oversight of the Secret Service in support of the House Task Force to deliver transparency, accountability, and solutions to ensure this never happens again.”

Ronald Rowe, the Secret Service’s second-ranking official, will take over as acting director, the Department of Homeland Security said. Rowe, a 24-year veteran of the agency, was appointed deputy director in April 2023, with responsibility for the agency’s daily investigative and protective operations.

President Biden issued a statement praising Cheatle’s decision to resign.

“As a leader, it takes honor, courage, and incredible integrity to take full responsibility for an organization tasked with one of the most challenging jobs in public service,” the president said. “We all know what happened that day can never happen again.”

Congressional inquiries into the assassination attempt were ongoing Tuesday as the news of Cheatle’s decision began to circulate. Rep. Mark Green (R-Tenn.), chairman of the House Homeland Security Committee, conducted a hearing with the commissioner of the Pennsylvania State Police, Col. Christopher Paris.

Green, in a statement, said he was “pleased that Director Cheatle finally did what she should have done days ago — resign.”

Cheatle returned to the Secret Service in September 2022 after taking a job as a top security official at Pepsi Co. North America.

Homeland Security Secretary Alejandro Mayorkas noted that decision in a statement Tuesday thanking her.

“Reflecting her devotion to country above all else, Director Cheatle returned from retirement to lead the agency and its noble mission that she loves and to which she has devoted her career,” Mayorkas wrote.

Bill Gage, a former Secret Service counterassault agent who worked on presidential protection during the Bush and Obama administrations, faulted Cheatle for failing to aggressively demand the resources that the Secret Service needs to perform its mission.

Gage said problems identified nearly 10 years ago in a series of Washington Post investigative stories, a bipartisan House Oversight Committee investigation and a blue-ribbon panel report commissioned by President Barack Obama — that the Secret Service was struggling with limited funds and staff and spread too thin to cover its expanding mission — remain largely unfixed.

“Every single director since 9/11 has totally dropped the ball,” he said. The directors “had an incredible opportunity to ask for more resources, and they have completely failed,” he added.

Last week, a group of Republicans furious over the assassination attempt trailed Cheatle through Fiserv Forum at the Republican National Convention, demanding that she explain the security failures.

“This was an assassination attempt!” yelled Sen. Marsha Blackburn of Tennessee, according to a video of the confrontation obtained by The Washington Post. “You owe the people answers! You owe President Trump answers!”

She and others expressed frustration that Cheatle did not answer their questions about the lapses.

“This is one of the greatest security failures in the history of the agency,” Blackburn said in a statement. “She can run but she cannot hide. She is a failed leader and she needs to immediately step down from her position.”

Trump, whose right ear was struck by a bullet, wore a bandage over it as he attended the convention. The attack killed one man and gravely wounded two others.

The shooting was the first time in decades that a U.S. leader was attacked while under Secret Service protection. In 1981, a gunman fired at President Ronald Reagan in Washington, wounding the president and three others.

Top officials at the U.S. Secret Service repeatedly denied requests for additional personnel and equipment sought by Trump’s security detail in the two years leading up to the rally shooting in Pennsylvania, according to four people familiar with the requests.

Agents charged with protecting Trump requested magnetometers and more agents to screen attendees at large public gatherings he attended, as well as additional snipers and specialty teams at other outdoor events, said the people, who spoke on the condition of anonymity to describe sensitive security discussions. The requests were sometimes denied by senior officials at the agency who cited reasons including a lack of resources at an agency that has struggled with staffing shortages, they said.

Secret Service spokesman Anthony Guglielmi said in a statement Wednesday night that Cheatle would not resign.

Cheatle said after the shooting that the Secret Service was cooperating with multiple investigations into the shooting, including a criminal probe led by the FBI and an independent review ordered by Biden.

When Biden named Cheatle as his Secret Service director in 2022, some inside the agency opposed her appointment, according to a half-dozen written complaints that Secret Service agents sent to The Post around that time and in the two years since.

In the complaints, her critics pointed to Cheatle’s lack of experience working in a senior post on a presidential protection detail — considered by many to be the pinnacle of agency service — and saying later in her tenure that she was excessively focused on hiring and promoting more women agents.

Cheatle’s handling of the shooting had further eroded support for her leadership inside the agency, according to a dozen current and former Secret Service officials who spoke on the condition of anonymity to avoid retribution. Many agents and Secret Service alumni were disturbed by the failure to sufficiently secure the rooftop that the gunman scaled, they said.

In addition, six of the former agents, all of whom have served in presidential protection details, told The Post that they found Cheatle’s public statements about security for the Butler, Pa., campaign event embarrassing.

They said they were particularly outraged by two comments she made in an interview with ABC News that aired days after the shooting.

First, she said local police were responsible for securing the Agr building on the outer perimeter of the event, implying that they were to blame for the gunman getting atop the roof and being able to shoot at Trump’s stage. Second, she said no officer was stationed on the roof that the gunman used in part because of a “safety factor” related to its slope. The Post previously reported that Secret Service countersnipers at the rally were positioned on steeper roofs.

The Department of Homeland Security has named an independent panel to review the security failures leading to the attack on Trump. The DHS inspector general, an independent watchdog who monitors and audits the agency, is also investigating the shooting.

Cheatle’s resignation caps a series of tumultuous years for the Secret Service, amid concerns that weak spots in the agency’s training, strategy and operations remain unresolved.

Before the shooting, the agency was scrutinized for deleting text messages that agents sent during Trump supporters’ Jan. 6, 2021, attack on the U.S. Capitol, depriving investigators of potentially valuable evidence. The agency said the messages were lost during a planned replacement of the agents’ devices.

The agency has faced various security lapses through the years.

In November 2011, a man armed with a semiautomatic rifle fired shots into the White House. Agents at first dismissed the noises as a construction vehicle backfiring and did not realize for four days that bullets had hit the residence.

In 2012, the agency was embarrassed by agents who brought prostitutes to their hotel rooms in Cartagena, Colombia, while arranging advance security for Obama’s visit to the city. In 2014, an armed security guard with an arrest record was allowed to share an elevator with Obama during a presidential visit to Atlanta.

Days later, a man carrying a folding knife jumped the fence outside the White House, sprinted past a Secret Service agent and made it into the East Room before being tackled by an agent.

Secret Service Director Julia Pierson, who in 2013 became the first woman to lead the agency, resigned in 2014.

A blue-ribbon panel named by the Obama administration in 2014 recommended sweeping changes to the agency, including intensifying training and calling for new leadership.

In 2015, the House Oversight Committee published a report finding that the Secret Service had fumbled its response to multiple security threats over several years.

After the shooting at the Trump rally, lawmakers and others expressed frustration that many of the called-for recommendations remained unimplemented.

Cheatle was the agency’s 27th director and the second woman to lead the agency. She was sworn in on Sept. 17, 2022.

Cheatle had spent more than 25 years in the Secret Service in various roles, including running the Atlanta office and then becoming assistant director of the Office of Protective Operations, the first woman in that role.

“That achievement in a male-dominated industry was not lost on me,” Cheatle said in a 2022 interview with Security magazine.

Cheatle served on Biden’s protective detail when he was vice president. Biden awarded Cheatle with a Presidential Rank Award in 2021 for her exceptional performance over time.

Josh Dawsey and Aaron Schaffer contributed to this report.