As BuzzFeed reports, FBI agents singled out Texeira partly because of billing details from Discord, the messaging platform he allegedly used to publish photos of the documents. The FBI also relied on an interview with a fellow member of the Discord server, who identified Texeira based on a driver’s license photo. And, as news spread about the leaked documents earlier in April, Texeira apparently searched the word “leak” on a government computer, and a monitoring system detected his activity.

“Accordingly,” reads an 11-page FBI affidavit, “there is reason to believe that Texeira was searching for classified reporting regarding the U.S. Intelligence Community’s assessment of the identity of the individual who transmitted classified national defense information.”

As The Boston Globe reports, Texeira’s work as a technology specialist at Otis Air National Guard base required a Top Secret security clearance, and his role as a “Cyber Transport Systems Journeyman” brushed up against systems with highly classified intelligence documents. Court papers showed that Texeira gained Top Secret clearance in 2021, at age 19 or 20.

Intelligence and cybersecurity experts told the Globe that rules surrounding classified documents were largely written long before the internet sped up the spread of information. They called the leak a national security failing, where Texeira obtained access to far more classified material than he needed to know, perhaps partly due to post-9/11 reforms that were intended to streamline information sharing.

According to The Washington Post, Texeira appears to differ from previous leakers of classified information because he had no motive other than to impress friends online. Others in the Discord chat group he frequented, dubbed Thug Shaker Central, said he seemingly just wanted to show off what he had access to and naively assumed his online pals would keep the information to themselves.

As The New York Times notes, it wasn’t immediately clear whether the Department of Justice would prosecute Texeira in Massachusetts, where he was arrested, or the Eastern District of Virginia, where the Pentagon sits. It was also possible that the case could go through the military court-martial system.