The FBI detained Jack Douglas Teixeira, a 21-year-old member of the United States Air National Guard, on Thursday in connection with sensitive document leaks that embarrassed Washington and its allies across the world.

Federal officials in an armored car and military gear stormed Teixeira’s home in Dighton, Massachusetts, a primarily wooded community of 8,000 people approximately 50 miles (80 kilometers) south of Boston.

The arrest comes a week after the leaks first became widely known, setting Washington on edge about the damage they may have caused. The episode embarrassed the U.S. by revealing its spying on allies and purported Ukrainian military vulnerabilities.

The leak of documents, posted largely on social media sites, was believed to be the most serious security breach since more than 700,000 documents, videos and diplomatic cables appeared on the WikiLeaks website in 2010.

Teixeira was an airman 1st class at Otis Air National Guard Base in Massachusetts, according to his service record. He joined the Air National Guard in 2019 and worked as a “Cyber Transport Systems Journeyman,” or an IT specialist.

Attorney General Merrick Garland told reporters Teixeira was wanted “in connection with an investigation into alleged unauthorized removal, retention, and transmission of classified national defense information.”

The FBI said its agents had conducted “authorized law enforcement activity at a residence in North Dighton, Massachusetts.”

Aerial news video showed Teixeira with his hands laced behind his head, walking backward toward the armored car with one officer watching from the turret. He was handcuffed and placed in the back of the vehicle. Garland said he was taken into custody “without incident.”