The man who jumped the White House fence last Friday was on the grounds for 20 minutes before he walked up to the back door of the White House and approached a Secret Service officer saying he had an appointment with the president, according to two Secret Service sources.

Even though the Secret Service's Uniformed Division searched for the intruder after he set off a series of alarms after jumping multiple fences, they found him only when he walked up to the officer posted at the "C-11" position, the back door of the White House's South Portico that leads into the dignitary reception area.

One source said the intruder, identified as Jonathan Tran, walked up to the back door and startled the officer standing there who didn't immediately think he was an intruder but some type of contractor because he was wearing khaki pants.

In previous reports, the Secret Service was not forthcoming about Tran's ability to elude them and did not disclose that he reached the back door.

In 2014, a different White House fence-jumper sprinted across the front White House lawn and through the front door, making it into the ceremonial heart of the first floor before a Secret Service agent who was finishing his shift wrestled him to the floor.

The Secret Service didn't initially disclose that he made it into the main floor of the White House until the Washington Post reported it. That incident, and several other security lapses, including a report by the Washington Examiner that President Barack Obama was mistakenly allowed to share an elevator with a man with a gun, led to Secret Service Director Julia Pierson's forced retirement.

New details emerging about the latest fence-jumping incident, which took place close to midnight on March 10, is drawing new congressional scrutiny of the Secret Service.

The incident took place just days after the latest director, Joseph Clancy, left the top job and retired. In his absence, the Department of Homeland Security selected William Callahan to serve as acting director. Clancy was chosen to replace Pierson after a series of embarrassing incidents came to light in 2014 and early 2015.

It also follows a Washington Examiner report that the top special agent in Colorado said she would rather face "jail time" than take "a bullet" for Trump in a Facebook post. She is on administrative leave pending an investigation.

Rep. Jason Chaffetz, R-Utah, earlier Friday sent Callahan a letter announcing that he had launched an investigation into the latest fence-jumping incident.

He cited an affidavit filed by a Secret Service Uniformed Division officer about the sequence of events that took place March 10. The affidavit was filed with the U.S. District Court for the District of Columbia. The arresting officer said the individual was carrying two cans of mace and "was walking close to the exterior wall of the White House mansion," and, at one point, hid "behind a White House pillar."

Chaffetz also wrote that the committee has received "allegations of additional information that was not included in the affidavit," including that the individual "may have triggered alarms that the Secret Service ignored, may have moved around the White House grounds undetected for a considerable amount of time, and may have attempted entry into the building."

"If true, the allegations raise questions about whether the agency's security protocols are adequate," he wrote.

"The Committee has longstanding concerns regarding repeated security incidents at USSS protected facilities," he wrote.

Chaffetz asked Callahan for the agency to provide a briefing to him at 5 p.m. on March 20 so the committee can "assess whether these allegations are true."

In addition, he asked for a series of documents and information by no later than 5 p.m., March 24, including: all video of the White House grounds during the hours in question, all logs of activity at the Joint Operations Center, all documents and communications related to any alarms on the White House grounds that may have been triggered during the time period, and all documents and communications referring or relating to the agency's awareness of and response to this March 10 security incident.