The head of the Secret Service said on Tuesday that she will resign following the attempted assassination of former President Donald Trump, which unleashed intense anger over how the agency tasked with protecting current and former presidents failed in its core mission.

Kimberly Cheatle, who has served as the director of the Secret Service since August 2022, faced increasing calls to resign and multiple investigations into how a shooter was able to get close to the Republican presidential candidate at an outdoor campaign rally in Pennsylvania.

In an email to staff obtained by the Associated Press, she stated, “I take full responsibility for the security breach.” "In light of recent events, I have made the difficult decision to resign from my position as your director with a heavy heart."

Cheatle's departure is unlikely to end the scrutiny of the agency, which has been plagued by turmoil following the failures on July 13, and comes at a critical juncture before the Democratic National Convention and a busy presidential campaign season. Legislators from both parties have vowed to continue the investigation, along with an inspector general’s probe and bipartisan independent effort launched at the request of President Joe Biden, which will keep the agency in the spotlight.

Cheatle said in her memo to staff: "The scrutiny over the past week has been intense and will continue as our operations ramp up."

Cheatle's resignation comes a day after she appeared before a congressional committee and faced hours of criticism from both Democrats and Republicans over security failures. She described the attempted assassination of Trump as "the most significant operational failure" of the Secret Service in decades and stated that she takes full responsibility for the security lapses, yet angered lawmakers by failing to answer specific questions regarding the investigation.

During the hearing on Monday, Cheatle remained defiant that she is "the right person" to lead the Secret Service, even as she acknowledged responsibility for the security failures. When Republican Representative Nancy Mace suggested Cheatle should start drafting her resignation letter from the hearing room, Cheatle replied, "No, thank you."

The shooter, 20-year-old Thomas Matthew Crooks, was able to get within 135 meters (157 yards) of the stage where the former president was speaking when he opened fire. This was despite a threat to Trump’s life from Iran, leading to extra security measures being provided to the former president in the days leading up to the July 13 rally.

Cheatle acknowledged on Monday that the Secret Service had been alerted to a suspicious person two to five times before the shooting at the rally. She also revealed that the roof from which Crooks fired had been identified as a potential weak point days before the event. However, she failed to answer many questions about what happened, including why there were no agents positioned on the rooftop.

Secret Service agents quickly escorted the bloodied Trump off the stage, and agency snipers killed the shooter. Trump stated that the top of his right ear was grazed during the shooting. One demonstrator was killed and two others seriously injured.

Cheatle told members of the House Oversight and Accountability Committee: “The attempted assassination of former President Donald Trump on July 13 is the largest operational failure of the Secret Service in decades.” She added, "As director of the United States Secret Service, I take full responsibility for any security error."

Details continue to emerge regarding warning signs on that day and the roles played by both the Secret Service and local authorities in security. The agency routinely relies on local law enforcement to secure the surroundings of events where protectees are present. Senior former Secret Service agents stated that the shooter should not have been allowed access to the roof.

Two days after the shooting, Homeland Security Secretary Alejandro Mayorkas expressed his "100%" support for Cheatle.

However, there were calls for accountability across the political spectrum, as congressional committees moved quickly to investigate, issuing a subpoena for her testimony, and senior Republican leaders in both the House and Senate called for her to resign. Biden, a Democrat, ordered an independent review of the security situation at the rally and the Secret Service's inspector general opened an investigation. The agency is also reviewing “the preparations and operations of the counter-sniper team.”

In an interview with ABC News two days after the shooting, Cheatle said she would not resign. She described the shooting as “unacceptable,” something no Secret Service agent would want to happen. She said that her agency is responsible for protecting the former president: “The buck stops with me. I am the director of the Secret Service."

Cheatle served with the Secret Service for 27 years. She left in 2021 to work as a security executive at PepsiCo before being asked by Biden to return in 2022 to lead the agency with a workforce of 7,800 special agents, uniformed officers, and other staff.

She took over amid controversy over missing text messages during the time when thousands of Trump supporters stormed the U.S. Capitol on January 6, 2021, following his loss to Biden in the 2020 election.

During her time with the agency, Cheatle was the first woman to be appointed as assistant director of protective operations, the division that provides protection for the president and other high-profile individuals, overseeing a budget of $133.5 million. She is the second woman to lead the agency.

When Biden announced Cheatle's appointment, he said she served under him when he was vice president and that he and his wife "trust her judgment and counsel."