Unknown intruder slipped undetected into home of national security adviser Jake Sullivan: AP sources

WASHINGTON - An unknown man managed to slip undetected inside the home of White House national security adviser Jake Sullivan, according to two people familiar with the incident. The U.S. Secret Service is investigating.

The door was apparently unlocked, and the intruder was able to get inside Sullivan's home around 3 a.m. last month, the people said. Secret Service is investigating whether the person intentionally went into the home or whether it was some kind of accident; the person appeared to be intoxicated, the people said. The people were not authorized to talk about an ongoing investigation and spoke to The Associated Press on condition of anonymity.

Sullivan has round-the-clock security. But the agents stationed outside his home did not know that the unknown male accessed inside the Washington home until the man had already gone. Sullivan came outside and told them, the people said.

Jake Sullivan

Security is always a top concern for high-level government officials, but there's been a more palpable sense of anxiety in recent years as threats to lawmakers and officials are on the rise. The husband of House Speaker Nancy Pelosi was attacked and severely beaten with a hammer by an assailant who broke into the couple's San Francisco in October.

There was no evidence that the person meant to harm Sullivan or even knew him. The Washington Post first reported the breach.

Meanwhile, additional security measures have been put in place outside Sullivan's home as a precaution while a review is conducted.

The U.S. Secret Service said in a statement that it was "examining a security incident that took place at a protectee site."

"While the protectee was unharmed, we are taking this matter seriously and have opened a comprehensive mission assurance investigation to review all facets of what occurred," according to the statement.

Any deviation from protocol was unacceptable, the Secret Service said.

Certain members of President Joe Biden's administration get a Secret Service security detail which means their homes are guarded and they receive protection as they move throughout their days outside the White House; it depends on a range of factors including the type of job and whether threats have been made.