Pierson’s undoing was not telling the president about a Sept. 16 incident in Atlanta in which President
Barack Obama rode an elevator with an armed security contractor during a visit to the Centers for
Disease Control and Prevention, two White House officials said. The armed contractor’s proximity to
Obama violated the agency’s security protocols.

Homeland Security Secretary Jeh Johnson as well as Obama appeared unaware of the full extent of the
Atlanta incident and the Sept. 19 security breach in which a man armed with a knife jumped the White
House fence and entered the building. Johnson, whose department oversees the Secret Service, was the
driving force behind Pierson’s resignation Wednesday, the officials said.

Since taking office last year Johnson had made it clear he wouldn’t tolerate even a whiff of scandal. He
had repeatedly expressed concern about the Secret Service performance in the wake of the White House
intruder, said the officials, who weren’t authorized to discuss the issue by name and requested
anonymity.

"In light of recent and accumulating reports about the agency, I think legitimate questions were
raised — at least they were in the mind of both the secretary and the president," said White House
spokesman Josh Earnest.

The White House learned about the Atlanta incident just before details of the encounter were published by
two newspapers. In a meeting with Johnson, Pierson offered her resignation without being asked, but
Obama had already told aides he thought she should go. No one put up any resistance when she offered to
step down, officials said.

Pierson did not respond to a telephone message from The Associated Press seeking comment. In an interview
with Bloomberg News, she said she felt leaving the agency "was the noble thing to do" and her
departure "would take pressure off the organization." She suggested she felt forced out of the
Secret Service after more than 30 years, just 18 months as director.

"Congress has lost confidence in my ability to run the agency," she said. "The media has
made it clear that this is what they expected."

The first clear sign of Pierson’s impending fate came Tuesday while she faced questions about the Sept.
19 breach from members of the House Oversight and Government Reform Committee.

She told lawmakers she could not explain why the agency issued conflicting statements on whether the
accused intruder was armed — court records say he had a 3-inch serrated folding knife — and how far into
the building he got. Omar Gonzalez was arrested and accused of running into the East Room, well beyond
the unlocked front door he was believed to have entered.

"I wish to God you protected the White House like you protected your reputation here today,"
Democratic Rep. Stephen Lynch told Pierson at the hearing.

Rep. Jason Chaffetz, a Utah Republican and senior member of the committee who knew about the Atlanta
incident before Obama, called for her ouster Tuesday night. After she resigned, he said, "It was
the right thing to do, it had to happen, but there are some systemic challenges that must be
addressed."

Pierson wasn’t the first Obama administration official to deal with a scandal, but how she handled it
contrasts starkly with others, including her immediate predecessor, Mark J. Sullivan.

Sullivan almost immediately suspended, fired or transferred implicated officers and agents in the
immediate aftermath of a 2012 made-for-the-tabloids prostitution scandal in Colombia. He also quickly
changed the rules governing employee behavior during work trips.

Pierson said Tuesday that personnel actions were pending.

Her departure wasn’t likely to end criticism of the agency. Lawmakers have called for an outside review
and Johnson has put Deputy DHS Secretary Alejandro Mayorkas and the department’s general counsel in
charge of the Secret Service investigation.

"We need a full, top-to-bottom review of the Secret Service and I will soon introduce legislation to
establish an independent panel to conduct this comprehensive assessment," said House Homeland
Security Committee Chairman Michael McCaul, R-Texas.

Obama hand-picked Pierson to lead the Secret Service after Sullivan retired last year, saying at the time
she was "eminently qualified" to lead the scandal-plagued agency. But she may not have had the
personal relationship with him that other presidents have shared with their Secret Service directors.
She never served on his protective detail and was focused more on the business of the agency than its
operations in the years leading up to her promotion.

Johnson earlier this year escorted Pierson to Capitol Hill when she briefed lawmakers after an employee
was found passed out drunk in a Netherlands hotel during a presidential trip. Johnson’s presence was a
clear sign of support that wasn’t replicated this week.

Any favor Pierson may have curried in Congress after the last time she explained an agency misstep
quickly vanished Tuesday. One by one, lawmakers on the powerful House committee — known as much for
partisan sniping as legislating — joined ranks to openly and aggressively criticize Pierson’s testimony
and her ability to run the agency in charge of presidential security.

"I think she had a disastrous appearance before our committee and I think it just made her continued
tenure untenable," Rep. Gerry Connolly, D-Va., said in an interview. "She sounded like a
police radio operator as opposed to the head of a major agency facing a crisis in confidence. She didn’t
rebuild confidence, she didn’t inspire, she showed no passion or sense of outrage even at what had
happened to her agency."

___

Associated Press writers Erica Werner and Eileen Sullivan contributed to this report.

___

Follow Alicia A. Caldwell on Twitter at www.twitter.com/acaldwellap