US Secret Service Director Julia Pierson resigned on Wednesday, appearing to take the blame for multiple breaches of security at the White House including a recent intrusion.
The day before, Pierson was questioned by a congressional committee about how a man managed to jump the White House fence and enter the building.
She admitted there had been “unacceptable flaws” in the protection of the US president and his family.
On September 19, Iraq War veteran Omar Gonzalez made it into the East Room with a knife before being disarmed and arrested.
The 42-year-old pleaded not guilty in court on Wednesday to unlawful entry while carrying a weapon.
Gonzalez, who suffers from post-traumatic stress disorder, was sent for a mental competency review.
Three days before the break-in, President Obama shared an elevator with a private security contractor who had a previous criminal record and was armed.
Pierson became the first female director of the Secret Service in March 2013.
At the time, she was lauded as the person to turnaround the agency’s tarnished reputation.