This story was originally posted at 4:12 p.m. It has been updated since then. 
 
 A man with a gun that the Secret Service did not know about rode in an elevator with President Obama during his visit to the Centers for Disease Control and Prevention in Atlanta on Sept. 16. 
 
 The previously undisclosed breach, confirmed by two sources familiar with the case, raises new questions about the agency's ability to protect the president. 
 
 The incident, which took place three days before an intruder jumped a fence and sprinted inside the White House, involved a failure in Secret Service advance work to prevent an armed man from coming into close proximity with Obama while he was visiting the CDC to receive a briefing about the Ebola threat. 
 
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 The threat to the president appeared minimal, but the incident alarmed agents on site and exposes a breakdown in several important Secret Service security protocols, the sources say. 
 
 The information comes the same day Secret Service Director Julia Pierson appeared before the House Oversight and Government Reform Committee and lawmakers publicly upbraided her for three hours about the Sept. 19 White House security breach, among other problems at the agency. 
 
 Lawmakers then questioned her during a session that was closed to the public Tuesday afternoon. 
 
 A source familiar with the case said Obama was in an elevator with his Secret Service security detail when a CDC security officer operating the elevator started taking photos and a video of the president with his phone and behaving unprofessionally. 
 
 Responding to the man’s behavior, one of Obama’s detail agents contacted a member of the protective intelligence team, on-site detectives who handle suspicious-activity cases, to collect the man and interview him. 
 
 When he didn’t deny taking the photos, his CDC supervisor, who was on hand for the interview, said the behavior was highly irresponsible and told him to hand over his gun, shocking the Secret Service officers who were questioning the man. 
 
 When agents ran a database check on the man, they discovered he had a criminal record, a source said. 
 
 Before the president travels anywhere, Secret Service agents make it their job to know who will have access to the president, and anyone with a gun needs special clearance and may not be allowed to carry it when the president is on site. 
 
 In addition to the Secret Service, only sworn law enforcement officers are allowed to be armed at a location where the president is visiting, the source said. Contract security officers are not allowed to be armed. 
 
 A Secret Service spokesman did not have an immediate response but said he would look into the matter and respond when he had more information. 
 
 Rep. Darrell Issa, R-Calif., chairman of the House Oversight and Government Reform Committee, said the incident is more evidence of the agency's problems. 
 
 “Given the Secret Service’s struggles to secure the White House, news of a security lapse while the president was traveling sounds like yet another symptom of systemic issues within the agency.” 
 
 Rep. Mike McCaul, R-Texas, chairman of the Homeland Security Committee, is calling for an independent top-to-bottom review of the agency and will introduce legislation creating a commission to conduct it. ||||| President Obama speaks at the Centers for Disease Control and Prevention in Atlanta on Sept. 16. It was during that visit that an armed security contractor was allowed to ride an elevator with Obama, in violation of Secret Service protocols. (Pablo Martinez Monsivais/AP) 
 
 Correction: This story has been updated to correct descriptions of the armed man who rode an elevator Sept. 16 in Atlanta with President Obama. While agents found he had prior arrests, according to people with knowledge of the incident, they found the man is not a convicted felon, as an earlier version reported. The Post reported new details provided about the man’s record here. 
 
 A security contractor with a gun and an arrest record was allowed on an elevator with President Obama during a Sept. 16 trip to Atlanta, violating Secret Service protocols, according to three people familiar with the incident. 
 
 Obama was not told about the lapse in his security, these people said. The Secret Service director, Julia Pierson, asked a top agency manager to look into the matter but did not refer it to an investigative unit that was created to review violations of protocol and standards, according to two people familiar with the handling of the case who spoke on the condition of anonymity. 
 
 The incident, which took place when Obama visited the Centers for Disease Control and Prevention to discuss the U.S. response to the Ebola crisis, rattled Secret Service agents assigned to the president’s protective detail. 
 
 The private contractor first aroused the agents’ concerns when he acted oddly and did not comply with their orders to stop using a cellphone camera to record the president in the elevator, according to the people familiar with the incident. 
 
 When the elevator doors opened, Obama left with most of his Secret Service detail. Some agents stayed behind to question the man and then used a national database check that found some prior arrests in his historyturned. 
 
 When a supervisor from the firm providing security at the CDC approached and discovered the agents’ concerns, the contractor was fired on the spot. Then the contractor agreed to turn over his gun — surprising agents, who had not realized that he was armed during his encounter with Obama. 
 
 Under Secret Service protocols, people with weapons, arrests or convictions for assault and related offenses or any history of mental illness are typically barred from having any access to the president. But it appears that this man, possessing a gun, came within inches of the president after undergoing no such screening. 
 
 Rep. Jason Chaffetz (R-Utah), who heads a House subcommittee that oversees the Secret Service, first heard of the breakdown from a whistleblower. The Washington Post confirmed details of the event with other people familiar with the agency’s review. 
 
 “Words aren’t strong enough for the outrage I feel for the safety of the president and his family,” Chaffetz said. 
 
 Chaffetz added: “His life was in danger. This country would be a different world today if he had pulled out his gun.” 
 
 A Secret Service official, speaking on behalf of the agency, said an investigation of the incident is ongoing. The official spoke on the condition of anonymity, citing the pending review. 
 
 A White House spokesman declined to comment on the incident or say when, or if, the president had been informed of it. 
 
 In response to a question at a combative House hearing Tuesday, Pierson said she briefs the president “100 percent of the time” when his personal security has been breached. However, she said that had happened only one time this year: when Omar Gonzalez jumped over the White House fence Sept. 19 and was able to burst into the mansion. 
 
 The revelation of the lapse in Atlanta is the latest in a string of embarrassments for the Secret Service. Some elements of the incident were first reported Tuesday afternoon on the Washington Examiner’s Web site. 
 
 Pierson drew criticism Tuesday from lawmakers in both parties during the hearing on her agency’s security lapses. The session focused on the Secret Service’s fumbled responses to the recent White House fence jumper and a 2011 shooting attack on the residence. 
 
 The fence breach came three days after Obama’s trip to Atlanta. 
 
 The elevator incident exposed a breakdown in Secret Service protocols designed to keep the president safe from strangers when he travels to events outside the White House. 
 
 Under a security measure called the Arm’s Reach Program, Secret Service advance staffers run potential event staff members, contractors, hotel employees, invited guests and volunteers through several databases, including a national criminal information registry, and records kept by the CIA, the National Security Agency and the Defense Department, among others. Anyone who is found to have a criminal history, mental illness or other indications of risk is barred from entry. 
 
 Local police and federal officers are not checked in the same way under the Arm’s Reach Program, with the Secret Service presuming that they meet the safety standards because of their employment in law enforcement. But private security contractors would typically be checked, said two former agents who worked on advance planning for presidential trips. 
 
 For nearly every trip the president takes, at least one person is barred from attending or participating in an event because of problems discovered in his or her background, the two former agents said. Most recently, a local political campaign volunteer who was offering to help drive staffers to and from events during a visit had faced an assault charge in the past. 
 
 As part of the Secret Service’s review of the elevator incident, Pierson directed a supervising agent on the president’s protective detail to stay in Atlanta to examine the breakdown. 
 
 That decision aroused suspicion on Capitol Hill. Chaffetz said he believes that Pierson was trying to keep another security gaffe quiet at a time when her agency and her leadership are under fire. 
 
 Former and current agents say Secret Service leaders prefer this kind of informal internal review for assessing potentially embarrassing mistakes. They say such reviews rarely lead to broad reforms or consequences. 
 
 These agents also say it is problematic for a presidential protective detail supervisor to review how his team performed. 
 
 In an incident The Post revealed in 2013, a top manager of the president’s protective detail had met a woman while drinking at a bar at the Hay-Adams hotel and had left a bullet from his service weapon in her room after spending the evening with her there. One of his superiors reviewed the incident and at first recommended that he receive a few days of counseling. The Post report about the episode led to the agency launching a fuller investigation. 
 
 Julie Tate contributed to this report.
– And the hits just keep on coming for the Secret Service: The Washington Examiner today reports on yet another serious lapse in security involving President Obama. The latest incident occurred just two weeks ago when the president traveled to Atlanta to visit the CDC—and ended up in an elevator with an armed man who has no fewer than three convictions for assault and battery. That's a lapse on two fronts, explains the Washington Post: Anyone in such close proximity to the president is supposed to be screened for weapons and criminal history. Unbeknownst to Secret Service agents traveling with Obama, this person had both. He was reportedly a contractor from a private security firm who was operating the elevator during the presidential visit. The man drew the attention of Secret Service agents when he refused to comply with orders to stop filming the president in the elevator with his smartphone. When agents questioned him afterward and then learned he had a criminal history, they called in his supervisor. The man got fired immediately and had to turn over his weapon to his boss—which is the first time the agents learned that he was armed. “You have a convicted felon within arm’s reach of the president and they never did a background check,” says Rep. Jason Chaffetz, a Utah Republican. “Words aren’t strong enough for the outrage I feel for the safety of the president and his family." (The agency's director was grilled on Capitol Hill today and promised reform.)