A California man carrying Mace roamed for nearly 17 minutes inside the secured White House perimeter before he was taken into custody March 10 near the South Portico entrance, the Secret Service acknowledged Friday.
The man did not enter the White House, the agency said, without further explaining the delay in his capture or details about alarms, protocols or responses that may have failed.
President Donald Trump was in the residence at the time of the breach.
Jonathan T. Tran, 26, of Milpitas, California, was detected crossing a five-foot outer fence near East Executive Avenue and the Treasury Department complex at 11:21 p.m. and was arrested at 11:38 p.m., the agency said.
The incident is believed to be the first intrusion on the White House grounds since Trump took office. Last year, the Secret Service added small spikes - or "pencil points" - to the top of the six-foot fence that surrounds the White House complex. The agency also announced a plan to raise the height of the fence to 11 feet by 2018.
To approach the mansion, Tran scaled two additional barriers, according to the Secret Service account, an eight-foot vehicle gate, then a 3 1/2- foot fence near the southeast corner of the East Wing.
Court documents filed at the time of his arrest omitted any reference to alarms sounding and gave only an account by the uniformed officer who saw and arrested Tran, up to 200 yards from where he had entered and after he had at one point hidden behind a pillar.
The agency said it has done more than 50 interviews and reviewed radio transmissions and video footage of the incident. It also said it has taken immediate but unspecified steps to mitigate lapses in security protocols as the investigation continues.
The disclosure Friday came as the Secret Service confirmed that a laptop computer holding sensitive security information was stolen from one of its agents in New York City, prompting a multiagency investigation to try to retrieve it.
The events renewed scrutiny of the presidential security agency battered and castigated after a 2014 incident in which intruder Omar Gonzalez made his way deep into the executive mansion before being tackled by an off-duty agent in the East Room. The incident and a string of other revelations triggered a management overhaul of the agency.
On Friday, a House Oversight Committee ordered the Secret Service to preserve documents in the March 10 episode and deliver a full briefing Monday.
"I worry this is the worst one yet," Rep. Jason Chaffetz (R-Utah) said in an interview. "The time on the White House grounds really concerns me. With the president in the White House, the intruder was evidently able to hide behind a pillar and get to a door undetected. The problem has persisted for years and is totally unacceptable. It scares me."
In a letter sent to Acting U.S. Secret Service Director William J. Callahan before the Secret Service released its new timeline of events, Chaffetz, chairman of the House Committee on Oversight and Government Reform, said his panel had received potentially troubling allegations about undisclosed breakdowns.
Chaffetz directed the agency to preserve and hand over all video of White House grounds from 10 p.m. to 1 a.m. that Friday night; all joint operations center activity logs; all documents and communications related to alarms, the incident and the agency response; and all subsequent reviews. "The individual may have triggered alarms the USSS ignored, may have moved around on the White House grounds undetected for a considerable amount of time, and may have attempted entry into the building," Chaffetz wrote.
"Time is of the essence," Chaffetz wrote. "The Committee has long-standing concerns regarding repeated security incidents at USSS protected facilities."
Jonathan Wackrow, a 14-year Secret Service employee who served in President Barack Obama's detail and now works in the private sector, has called the incident a "gut punch" to an agency still recovering from the Gonzalez incident.
Tran, who was carrying a backpack and two cans of Mace, was charged with entering or remaining on restricted grounds while carrying a dangerous weapon and faces a statutory maximum of 10 years in prison if convicted. A U.S. magistrate this week released him to his family's home in Northern California on personal recognizance subject to court and electronic monitoring, mental evaluation and treatment if necessary.
Tran also had been carrying a book on Trump, a U.S. passport and a laptop containing a letter addressed to the president about Russian hackers, saying Tran had found "information of relevance," according to a criminal complaint filed March 11.
Tran stated he had jumped the fence and added, "I am a friend of the president," Secret Service officer Wayne Azevedo wrote in an affidavit.
Trump last weekend praised the Secret Service for doing "a fantastic job" responding to a "troubled person."
In the New York City laptop theft, the Secret Service said that "an employee was the victim of a criminal act in which our agency-issued laptop computer was stolen.''
The agency tried to dispel concerns about potential security risks, saying their agents' laptops "contain multiple layers of security including full disk encryption and are not permitted to contain classified information.''
The agency did not say what sensitive information might be on the laptop, but one law enforcement official said it contained building and security plans for Trump Tower, home of the president and his family.
The official said the device was stolen from a vehicle in the driveway of the agent's home in Brooklyn on Thursday morning. The computer was in a bag that was later recovered, but the laptop was no longer in it, the official said. A personal laptop was also in the bag and taken by the thief, but officials are less concerned about the data on that device, the official said.
Authorities have recovered video of a man walking away.
The Washington Post's Carol Leonnig contributed to this report.