When the Secret Service Fails

10-1-14 White House Fence
The White House seen from outside the north lawn fence in Washington September 22, 2014 Kevin Lamarque/Reuters

The Secret Service is used to having its focus on the president of the United States. But it's the agency that has been in focus this week, with recent lapses in security resulting in the resignation of Secret Service head Julia Pierson and providing the media ample opportunity to revisit the agency's past mistakes.

News that a gun-toting security contractor rode in an elevator with the president, that a knife-carrying fence-hopper made his way far into the White House and new details of a 2011 shooting incident on the grounds have thrown the Secret Service into the limelight. It's not the agency's first time there.

The Secret Service began protecting presidents in 1901, after the assassination of William McKinley, according to the agency's website. In an early breach of the White House, a man who called himself "Mr. John Smith" visited Theodore Roosevelt, insisting he had an appointment, according to the New York Times's "An Ever-Expanding List of Unwelcome Visitors to the White House." He didn't have an appointment, but he did have a large-caliber pistol in his back pocket.

The second Roosevelt to take the office, Franklin Delano, once found an uninvited guest standing in the room next to him when the lights came back on after he had finished watching a movie.

On Christmas in 1974, a man drove his car into a White House gate, according to a compilation by New York magazine of "The 7 Weirdest White House Security Breaches." He stepped out and demanded to see the Pakistani ambassador, all while covered in what appeared to be explosives, which later turned out to be flares. Gerald Ford was on vacation that day, but less than a year later, on Thanksgiving night, a man approached Ford's daughter, Susan, after hopping the White House fence and hiding in the bushes.

The Obama administration has had its fair share of security problems. The Guardian's "handy guide" to "Secret Service slip-ups" cites a 2012 prostitution scandal which implicated a dozen secret service agents from the president's security detail and an infamous party-crashing incident by Michaele Salahi, of The Real Housewives of D.C., and her husband at the White House in 2009. The couple had not been invited but nevertheless made it past two security checkpoints and an ID requirement and into close quarters with Joe Biden, with whom they posed for a photo.

Pierson told Congress Tuesday that Iraq veteran Omar Gonzalez is not the first to have hopped the fence, The New York Times reported: In the past five years, 16 have done so, and six of those incidents were just this year. Gonzalez pleaded not guilty to his breach of the White House Wednesday.

The seriousness of the incident—which saw Gonzalez sprint through the front door carrying a knife—might have been the final straw: Pierson handed in her resignation Wednesday.

Meanwhile, Jeh Johnson, secretary of the Department of Homeland Security, took aim at critics in his statement on Pierson's resignation.

In the last week, the Secret Service has completed "highly complex and demanding assignments without incident," the statement read. "There is no other protection service in the world that could have done this."