Famed US Secret Service in hot seat after Trump shooting

Within minutes of the attempt on Donald Trump's life at a campaign rally, the US Secret Service faced a wave of criticism for failing its "no fail" responsibility: ensuring the safety of its high-profile protectees.

President Joe Biden announced on Sunday that he had ordered an independent review of the agency's handling of the shooting in Butler, Pennsylvania, where one attendee was killed and Trump was injured in the ear before the gunman was shot dead. Republican leaders in Congress have also announced a probe.

While new information emerges about the campaign-altering incident, key questions remain about who was responsible for what safety roles at the rally, and why the roof used by the would-be assassin was not secured.

Here is some key background on the Secret Service and probes into the attempted assassination:

Who helps the Secret Service protect top officials?

"The buck stops with me," the director of the US Secret Service, Kimberly Cheatle, said in an ABC News interview broadcast on Monday, two days after the shooting.

She explained that the building where the shooter was located had been in the "outer perimeter" of the rally, which fell under the responsibility of local police.

"There was local police in that building -- there was local police in the area that were responsible for the outer perimeter of the building," she said, without accounting for how the shooter was not prevented from climbing on the roof.

During presidential campaigns, the Secret Service must "draw upon resources, not only across the federal government, but with state and local law enforcement," Secretary of Homeland Security Alejandro Mayorkas, whose department overseas the Secret Service, told reporters Monday.

Who does it protect?

The Secret Service provides lifelong protection for current and former presidents and vice presidents, their families and the children of former presidents up to the age of 16.

Its agents also provide security for foreign heads of state and government on official visits to the United States, or for major national or international events.

What is its mission and size?

Originally set up to combat counterfeit currencies, the agency was entrusted with protecting senior US leaders and their families following the assassination of President William McKinley in 1901.

To this day, the Secret Service continues to play a role in protecting the US financial system, including by investigating counterfeit money and digital fraud.

The agency has over 6,500 personnel, about half of whom are special agents, famous for their dark glasses, suits, earpieces and serious expressions.

Who oversees the agency?

For most of its history since being created in 1865, the agency was part of the Treasury Department.

But in 2003, it was moved under the newly created Department of Homeland Security.

Cheatle became its director in September 2022, after a stint in the private sector as PepsiCo's head of security following a 27-year career with the Secret Service.

The Republican chairman of the House Oversight Committee has scheduled a hearing for Cheatle to testify on July 22.

What lessons will be learned from the investigation?

Biden administration officials said they would not get ahead of the "independent" probe before announcing conclusions.

Mayorkas, who voiced "100 percent confidence" in Cheatle, said the review will "examine the Secret Service's and other law enforcement actions before, during and after the shooting" to identify any measures needed to be taken to ensure the agency's "no fail mission of protecting national leaders."

He hinted at possibly asking Congress for additional funding to enable the Secret Service to rely less on local police.

Trump's security detail has been adjusted following the assassination attempt "to ensure his continued protection for the convention and the remainder of the campaign," Cheatle said in a statement.