Trump's shooting puts scandal-plagued Secret Service under the biggest microscope yet

• The Secret Service is facing tough questions after an assassination attempt on former President Donald Trump.
• The powerful agency has rocked by scandals in recent years.

The Secret Service has been at the center of scandals in recent years.

Jaw-dropping breaches and embarrassing indiscretions ended the careers of some agents and led lawmakers to harangue top officials.

But all of those episodes pale to what will happen after Saturday's assassination attempt on former President Donald Trump, a shocking breach that was an inch from utter disaster.

Trump was speaking at a rally in Pennsylvania when a gunman — later identified as a 20-year-old man from the area — opened fire at the former president.

Trump's ear was pierced by a bullet; a rallygoer near the president was killed before Secret Service agents shot and killed the would-be assassin.

Trump, President Joe Biden, and scores of other leaders praised the Secret Service for its quick response.

But already, it is becoming clear that the agency's task with keeping the president, former president, and other world leaders when they are in the US safe will face intense scrutiny.

As closely scrutinized as the agency has been, nothing has prepared it for what is likely to come.

Biden himself said Sunday he's ordered an independent investigation into the rally shooting.

And House Speaker Mike Johnson, the nation's most powerful Republican, quickly vowed that Congress would conduct a full investigation into what happened.

Lawmakers and experts alike have been shocked how the shooter was able to get close enough to the rally site that it was within shooting range.

"The seriousness of this security failure and chilling moment in our nation's history cannot be understated," House Homeland Security Committee Chairman Rep. Mark Green, a Tennessee Republican, said in a letter to Homeland Security Secretary Alejandro Mayorkas. "No assassination attempt has come so close to taking the life of a president or presidential candidate since President Reagan was shot in 1981." (The Secret Service is under the Homeland Security Department.)

The past scandals can also shed some light on some of the biggest issues plaguing the agency: shocking security lapses.

Agents went wild while in Colombia for a presidential visit, including hiring prostitutes.

What happened: In April 2012, several Secret Service agents preparing for President Obama's visit to Colombia as part of the Summit of the Americas hired prostitutes.

The scandal rocked the agency to its core. President Obama, who repeatedly expressed his admiration for agents' bravery, said at the time he would be "angry" if the allegations were proved to be true.

The aftermath: Of the 13 agents suspected of soliciting prostitutes, six resigned or retired, according to an inspector general's report released roughly a year after the incident.

Four more had their security clearances revoked. The inspector general found that although individuals engaged in misconduct, there was no evidence "misconduct is widespread in USSS."

Journalist Carol D. Leonnig, who won a Pultizer Prize for her coverage of the Secret Service's scandals, later called into question the finding that Colombia episode was just a one-off incident.

"And in fact, what agents told me in the wake of this series of investigations, what they told me was this happened all the time," Leonnig later told NPR.

Secret Service Director Mark Sullivan, who retired not long after the scandal, testified to Congress that some of his agents "did some really dumb things."

A knife-wielding intruder makes it all the way into the East Room.

What happened: In September 2014, Omar J. Gonzalez, who was carrying a knife, jumped the fence and got into the White House. President Barack Obama was not home at the time of the incident. Gonzalez only made it into the White House briefly, but his actions came on the heels of 16 separate fence-jumping incidents in the five years before his brazen act, according to The New York Times.

The aftermath: Secret Service Director Julia Pierson was already embattled before the incident. In a separate scandal, an armed security contractor had gotten onto an elevator with Obama. The combined weight of the scandals led Pierson to resign.

Two Secret Service agents, who had 'likely' been drinking, crashed a car on the White House grounds.

What happened: In March 2015, two Secret Service agents crashed a car on the White House grounds while the complex was under a heightened security state to investigate a suspicious package. Both agents were high-ranking, including Marc Connolly, the Deputy Special Agent in charge of the Presidential Protective Division (PPD.

Among Connolly's responsibilities was handling "all aspects of White House security."

Homeland Security Inspector General John Roth, a government watchdog, later concluded "it was more likely than not" that the agents' "judgment was impaired by alcohol." Roth's report found that the agents had attended a retirement party and run up quite the tab at a Washington, DC, bar before the incident. Neither of the agents alerted their supervisors of what happened. Both of the agents denied in their interviews with the inspector general that they had drank to excess.

The aftermath: Connolly announced his retirement ahead of the release of the inspector general's report. George Ogilvie, the assistant special agent in charge of the agency's Washington field office, was placed on administrative leave, according to The Guardian.

White House fencer jumper wanders the grounds for more than 15 minutes.

What happened: In March 2017, Jonathan T. Tran scaled multiple fences and was able to approach the White House's south portico just before midnight. President Donald Trump was asleep inside the residence at the time. Tran also looked into windows. Secret Service later apprehended him. He had cans of mace on him.

The aftermath: According to CNN, two Secret Service officers were fired after the incident. Tran had set off multiple alarms before he was discovered. A White House security review was also conducted. Before the breach, the Secret Service had already announced efforts to beef up the fence around the White House, including adding small spikes atop a six-foot fence, according to The Washington Post.

The Secret Service caught wind of threats before January 6.

What happened: According to the House January 6 committee, the Secret Service was among the federal agencies that received warnings that the far-right Proud Boys and Oath Keepers were planning for potential violence on January 6, 2021, during the joint session of Congress that was responsible for formally counting the Electoral College votes for the 2020 presidential election.

Agents were also praised for how they kept Vice President Mike Pence safe as rioters ransacked the Capitol. Pence declined to leave the Capitol complex, which his security detail advised him to do.

The aftermath: After the deadly attack on the Capitol, the Secret Service was also criticized after lawmakers asked for text messages sent around the time of the riot — which the agency said had been deleted.

The Secret Service denied any wrongdoing.