The veteran carrying a knife who scaled the White House fence and sprinted inside the executive mansion made it far farther than was originally known, according to multiple media reports.
Originally, it was suggested that 42-year-old Omar Gonzalez was detained in the building's foyer, almost immediately after entering the front door.
Secret Service agents had also muted an alarm box near the front of the building that would have alerted them of the intruder and signaled them to lock the doors, an agency official told the Post.
Secret Service spokeswoman Laura Topolski said the agency was not commenting on the reports "due to the ongoing investigation."
The new revelations will heighten the drama on Tuesday, when agency director Julia Pierson is expected to testify before the House Oversight Committee.
The Secret Service has ordered a full review of agency policies and procedures following the incident, and already installed new temporary fencing around the White House compound.
Pierson told the The New York Times the agency would "leave no stone unturned" in the investigation.
“I am committed to a full and robust fact-finding that allows me to look at what went wrong,” she said.
Lawmakers expressed alarm over the latest revelations on Monday.
“If true, the fact that crash boxes were muted to avoid being ‘disruptive’ is not due to a lack of resources or an insufficient number of checkpoints or barriers,” Rep. Jason ChaffetzJason ChaffetzSenate passes dozens of bills on way out of town Oversight panel demands answers on Pentagon waste report Chaffetz: Congress will ‘absolutely’ look at 5B in waste at Pentagon MORE, (R-Utah), chairman of a House Oversight subcommittee on Homeland Security, told the Post.
Chaffetz described the incident as a "failure of leadership."
“The agency needs a solution that goes deeper than more fences and more people,” Chaffetz said. “It must examine what message is being sent to the men and women who protect the president when their leader sacrifices security to appease superficial concerns of White House ushers.”
According to reports, the alarm boxes had been muted by the Secret Service apparently at the request of White House ushers.
Earlier Monday, White House press secretary Josh Earnest said the president retained confidence in the agency and Pierson.
"The president does have full confidence in Director Pierson and other members of the Secret Service to do their very important work," Earnest said.
The White House spokesman added that "it is an issue that the president is obviously concerned about."
"That’s something that he will review once they’ve had a chance to conduct their investigation of what exactly happened 10 days ago," he continued. "That will be part of a broader review of the security posture here at the White House. And we’re looking forward to the results."