When the bullets started flying at the Butler Farm Showgrounds in Pennsylvania last month, it wasn’t the U.S. Secret Service that saved Donald Trump’s life.

It was luck.

The former American president and the 2024 Republican presidential candidate turned his head at the exact moment the first bullet grazed his ear, instead of suffering far more serious consequences.

But this is not the first time that the Secret Service, whose primary job is to protect American political leaders, has failed.

And with this year’s presidential campaign in full swing, the agency is under enormous pressure to learn from its mistakes.

What is the Secret Service?

The Secret Service was established in 1865 under the United States Department of the Treasury, with the primary purpose of investigating and intercepting counterfeit money.

“After the Civil War, a large portion of the money in circulation was counterfeit, up to a third of it,” says Gray, who is now at the University of New Haven.

But in 1901, President William McKinley was assassinated by an anarchist named Leon Czolgosz, and the United States Congress assigned the Secret Service to protect the president.

Today, the Secret Service is part of the U.S. Department of Homeland Security. The agency protects U.S. political leaders, their families and visiting dignitaries, and, true to its roots, continues to investigate financial crimes.

Secret Service special agents have become a familiar sight in the American political arena. In their famous suits and earpieces, they are men and women willing to give their lives for those they serve.

The assassination of JFK

In 1963, President John F. Kennedy visited Dallas, Texas.

The 46-year-old Democrat had been in power for nearly three years and had come to Texas to calm some intraparty strife. It was also a soft start to his 1964 re-election campaign.

But as Kennedy’s motorcade passed through Dealey Plaza, he was shot. He died about 30 minutes later in the hospital. Lee Harvey Oswald was arrested and charged with the murder, but was fatally shot a few days later.

The assassination of President Kennedy had a major impact on the Secret Service.

The Warren Commission was set up to investigate what had happened. It found that many of the agency’s procedures were inadequate for a president like JFK, who enjoyed being in the middle of large crowds.

“Every time there is an attempted assassination or a successful assassination attempt, the Secret Service learns from it and adjusts the way it conducts security,” Gray said.

Furthermore, no one had thought to thoroughly check the buildings along the route of the procession or to deploy security. There were also no formal procedures for cooperation with the local police. That has all changed in the meantime.

There were also only a few dozen agents on the ground in Dallas when JFK was shot. So after that, the Secret Service got more money to recruit and expand its operations.

Two assassination attempts within weeks

In 1975, President Gerald Ford was targeted by two different assassins within a few weeks.

On September 5, Lynette “Squeaky” Fromme of the Manson Family cult tried unsuccessfully to shoot him in Sacramento.

On September 22, Sara Jane Moore fired two shots at Ford outside a San Francisco hotel. Both shots missed.

Former Special Agent Robert McDonald spent 21 years with the Secret Service, serving as a security guard for presidents, among other positions.

He says that after the events at Ford, there has been a major change around the doors of cars or planes waiting for a president.

“The officers couldn’t get the door of the limousine open (so Ford could get in)… (So now) when you see the president get out of the vehicle or walk up to it, that door is already open,” he said.

He says every event like this is “a building block” of how the Secret Service operates.

The assassination attempt on Reagan

In March 1981, Ronald Reagan, the movie star turned governor and president, gave a speech at the Washington Hilton.

As Reagan left the event and walked toward his motorcade, he was shot by John Hinckley Jr.

Secret Service agent Jerry Parr managed to get Reagan into his presidential limousine and arranged for him to be driven immediately to a nearby hospital, rather than back to the White House.

The Republican president was seriously wounded but recovered. Two others were injured and one, press secretary James Brady, died years later from his wounds.

Bill Gage was a young boy at the time and he can still remember seeing the news about the attempted assassination on television.

“When I saw those guys in suits, throwing themselves in front of the bullets and then I asked my dad, ‘Hey, who are those guys?’ … My dad said, ‘That’s the Secret Service,’” he says.

“That’s when I knew that’s what I wanted to do.”

Years later, Gage became a special agent for the Secret Service, and he never forgot Jerry Parr’s actions.

“A doctor said Reagan had only minutes to live if he didn’t get medical treatment. Jerry Parr saved Reagan’s life,” he says.

What exactly went wrong that day?

There was a screening process for attendees of Reagan’s speech at the hotel, but after pressure from the White House, a group of people were allowed to stand outside the venue without screening.

Among them was the shooter, John Hinckley Jr.

“I think the most important lesson we learned from the Ronald Reagan shooting is that you can’t let the White House thwart your plan to prevent a threat from getting so close to the president,” Gray said.

And in the decades since, the Secret Service has meticulously prepared for major events.

For example, Robert McDonald lived in Hawaii for 16 months to plan the two-day APEC summit in 2011.

“We had to get hotel rooms. We had to fly in all the armored limousines. We had to figure out with our military partners how to protect Waikiki from trouble. It was a very tough assignment.”

But that doesn’t mean every event is foolproof.

People ‘must be held accountable’

Several things went wrong on the day of Trump’s assassination attempt, from seating arrangements to communication errors.

Questions have been raised about the work done by Secret Service agents leading up to the meeting.

“These are the officers who come in advance and put together the security apparatus and the plan. They prepare it, they assess it, they brief it, they bless it, they supervise it, they execute it,” McDonald said.

“That’s where (the Secret Service) really made some serious mistakes that need to be addressed, and some people need to be held accountable.”

The Secret Service relies in part on local law enforcement to secure locations.

Gray says this time the Secret Service assumed that local snipers would be guarding the roof of the warehouse, where gunman Thomas Matthew Crooks fired his shots.

But these snipers were actually in an adjacent building, a plan that was reportedly approved by someone in the Secret Service.

Crooks was initially identified by local police as someone acting suspiciously, but he then disappeared into the crowd.

“A (local police) team that was responsible for protecting former President Trump from that building had abandoned their post because they wanted to get this guy. So that was the biggest deficiency,” Gray explained.

By the time Crooks was found by local police, he was on the roof and about to take aim at Trump.

After the shots were fired, Crooks was killed within seconds by a Secret Service sniper.

The fallout for the Secret Service is already dire. During a U.S. Congressional hearing on oversight, Director Kimberly Cheatle failed to answer basic questions about the event and was forced to resign days later.

All this and much more will be investigated as part of several studies that have already been launched.

What will change after Trump’s shooting?

The US presidential election is still months away, meaning there will be a lot more campaigning ahead for Trump and his new Democratic rival Kamala Harris.

Will the assassination attempt change the course of events?

“If (former) President Trump decides to continue hosting outdoor gatherings, there will not be a roof within a mile of that gathering that is not covered,” McDonald said.

And changes are already underway. This week, Trump held his first outdoor rally since the shooting, behind a large bulletproof enclosure.

Cheryl Tyler, the first black woman assigned to the Secret Service’s Presidential Protective Division, believes a similar campaign style will continue.

“Politicians in the United States need to put their foot down. They want to meet the people,” she says.

“(And) people are saying, ‘You shouldn’t have outdoor events.’ Well, I’m sorry, that’s never going to happen in American politics.”

She says there will be more negotiations between the Secret Service and campaign teams about how this can be done as safely as possible.

McDonald adds that bigger changes may be implemented in the future.

“(The Secret Service) is investigating a lot of different things and maybe they should narrow that list down,” he said.

“I think (the agency) should use this incident as an opportunity to start over and reset its priorities.”

In other words, more time, effort and resources must be put into the most important task: protecting American political leaders.