The Secret Service said it was investigating how an intruder was able to enter the home of President Biden’s national security adviser last month even though a full security detail was posted outside.
Jake Sullivan, the national security adviser, was not harmed during the breach, the agency’s spokesman, Anthony Guglielmi, said in a statement on Tuesday, adding that the identity of the intruder remained unknown.
Mr. Sullivan, 46, lives in the West End neighborhood of Washington with his wife, Margaret Goodlander, a deputy assistant attorney general in the Justice Department’s antitrust division. The person entered Mr. Sullivan’s house at 3 a.m. on April 29, the Secret Service said.
Mr. Sullivan noticed the intruder — a man who appeared to be intoxicated — and told him to get out, according to people familiar with the episode who spoke on the condition of anonymity because of the continuing investigation. The intruder left, and Mr. Sullivan alerted the Secret Service agents posted outside. Officials are investigating whether the intrusion was an accident or if the intruder had criminal intent.
“Any deviation from our protective protocols is unacceptable and if discovered, personnel will be held accountable,” Mr. Guglielmi said. “Modifications to the protective posture have also been made to ensure additional security layers are in place as we conduct this comprehensive review.”
The Washington Post first reported the episode. The White House declined to comment.
Mr. Sullivan served as Mr. Biden’s national security adviser when he was the vice president during the Obama administration and as Hillary Clinton’s deputy chief of staff when she was the secretary of state.
The Secret Service, which is tasked with protecting the president, senior administration officials and former presidents, has previously been criticized for its protective security details. In September 2014, an intruder entered the White House, and a review found that the man charged in the breach, Omar Gonzalez, was able to climb the fence and get into the mansion because of a series of “performance, organizational, technical” and other failures by the Secret Service.
Adam Entous and Michael D. Shear contributed reporting.
