Secret Service Director Julia Pierson testifies before the House Oversight and Government Reform Committee about the White House perimeter breach during a hearing on Tuesday. Pierson stepped down from her position on Wednesday. Chip Somodevilla/Getty Images hide caption

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This 2009 photo provided by Jerry Murphy shows Omar Gonzalez, who was married to Murphy's mother, Samantha, until they divorced in 2012. Authorities have identified Gonzalez as the man who got into the White House after scaling a fence on Sept. 19. AP hide caption

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This 2009 photo provided by Jerry Murphy shows Omar Gonzalez, who was married to Murphy's mother, Samantha, until they divorced in 2012. Authorities have identified Gonzalez as the man who got into the White House after scaling a fence on Sept. 19. AP hide caption

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Secret Service director Julia Pierson enters a hearing room in April to answer questions before a closed meeting of the Senate homeland security committee in Washington. Today, Pierson will appear before a House committee to respond to questions about White House security breaches. Cliff Owen/AP hide caption

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A Secret Service police officer stands near an entrance to the White House complex during an evacuation, minutes after President Barack Obama departed Washington for Camp David aboard Marine One. A man scaled a fence and reached the residence last night. Evan Vucci/AP hide caption

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Mark Sullivan, Director of the United States Secret Service, at a hearing of the Senate Homeland Security and Government Affairs Committee in May of 2012. Brendan Smialowski /AFP/Getty Images hide caption

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Before the vote, GOP nominee Mitt Romney and his running mate (Rep. Paul Ryan, in the background) were guarded by watchful Secret Service agents. After results came in, the agents quickly disappeared. Justin Sullivan/Getty Images hide caption

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