Now that Julia Pierson has officially resigned as the director of the U.S. Secret Service, her position will be filled by interim director Joseph Clancy, formerly a special agent in charge of the Presidential Protective Division of the Secret Service.

Pierson, the first woman to serve as the director of the Secret Service, resigned Wednesday afternoon after a string of security breaches came to light, including an Army veteran who climbed over a White House fence and ran into the East Room with a knife on Sept. 19. The White House intruder, who has been identified as 42-year-old Omar J. Gonzalez of Copperas Cove, Texas, was eventually arrested. Officials also found 800 rounds of ammunition, two hatchets and a machete in his vehicle, which was parked nearby, reports NBC News.

It was also revealed that an armed security contractor with an assault record got onto an elevator with President Obama while he was visiting Atlanta on Sept. 16, according to reports by the Washington Post.

Pierson's resignation comes 18 months after President Barack Obama appointed her as the new director of the top law enforcement agency after its reputation had been tarnished by a prostitution scandal.

On Wednesday, Homeland Security Director Jeh Johnson released a statement announcing that Clancy will replace Pierson for the time being.

Clancy, 58, retired from the agency in 2011 and began working as the head of security at Comcast, which owns NBCUniversal.

"I appreciate his willingness to leave his position in the private sector on very short notice and return to public service for a period,'' Johnson said, according to USA Today.

Clancy studied at the United States Military Academy at West Point and graduated from Villanova University in Pennsylvania. He then worked as a schoolteacher for a few years before he joined the Secret Service in Philadelphia in the 1980s. While there, he worked in the New York field office overseeing a team of agents and major investigations. He was also responsible for heading security at national special events before he joined Obama's protective detail.

"He is somebody who has earned the respect and admiration of the men and women who are his colleagues at the United States Secret Service," White House Press Secretary Josh Earnest said, reports The New York Times. "He is also somebody who has the full confidence of the president and the first lady."

Former Secret Service Director John Magaw said Clancy is the "perfect" person for the position and described him as one of the most "versatile'' executives to serve the agency.