Jack Teixeira, 21, was charged on Friday in US District Court in Boston with unauthorised removal and retention of classified and national defence information – a breach that has caused an international uproar and exposed explicit US assessments on the war in Ukraine and other closely held secrets.

A magistrate judge ordered Teixeira held until a detention hearing next week.

Two of his former classmates told The Boston Globe that Teixeira revered the military and showed an early interest in joining. He was especially focused on the history of war and weapons.

“From a young age, I remember he would have a book on, I believe, US military aircraft, armaments, like a real big textbook,” John Powell told the Globe.

Though Powell remembered Teixeira being bullied in middle school, he told the newspaper the young man was an optimist and “sweetheart” with an especially close relationship with his stepdad, an air force veteran.

High school classmate Kailani Reis told the newspaper Teixeira was “super quiet” and gave off “loner vibes”, while another classmate, Sarah Arnold, told The Associated Press news agency she remembered him as being quiet and keeping to himself.

Discord

Teixeira enlisted in the Air National Guard in September 2019, according to military records. He graduated from Dighton-Rehoboth Regional High School the following year, when the COVID-19 pandemic forced the school to close and go virtual.

It was during the pandemic that Teixeira developed a close relationship with other members of a chat room on the social media platform Discord, where members of the group have said the leaks showed up. The chat app is used by video gamers and others to connect online.

A member of the Discord chat group spoke to AP about the conversations, but declined to give his name, citing concerns for his personal safety. The group, called “Thug Shaker Central”, drew people who talked about their favourite types of guns and shared memes and jokes, some of them racist and anti-Semitic, the person said.

The group also included a running discussion about Russia’s invasion of Ukraine. For months, a member nicknamed “the OG” posted reams of classified material, said the Discord member who confirmed that OG was Teixeira.

Teixeira liked to chat about guns, was an observant Christian, and would often pray with group members, the fellow member said. In recent months, Teixeira had become disillusioned about the US military and had begun to express “regret [about] joining”, the person said. “He even said he’d kick my a** if I thought about joining.”

Teixeira also worried the federal government had become too powerful, according to the Discord user.

The chat group member said he was not sure why Teixeira enlisted, but believed he needed money for college. He added that OG was skilled at making memes.

“He was good at his craft. He was good with, you know, Photoshop,” the group member said, adding Teixeira “was never a very, super serious guy, usually was all like laughs and giggles”.

Teixeira was recently promoted to Airman 1st Class and assigned to the 102nd Intelligence Wing at Otis Air National Guard Base, where his job was listed as a cyber-transport systems journeyman.

Despite his relatively low rank, the technology position would have given Teixeira responsibility for maintaining computer networks with access to classified information. Teixeira began active duty in October 2021.

Members of the Discord group described Teixeira as someone looking to show off rather than being motivated by a desire to inform the public about US military operations or to influence US policy.

The Discord member said he did not believe Teixeira leaked documents to undermine the US government or for an ideological reason.

“If I had to give a gauge on it, it would be more or less just some nerds wanting to glance over some stuff and compare and contrast and kind of have a little joke about it,” he said.

“At the end of the day, I mean we’re just trying to have a fun time.”

US Attorney General Merrick Garland said there were “very serious penalties” associated with the crimes allegedly committed by Teixeira.

“People who sign agreements to be able to receive classified documents acknowledge the importance to the national security of not disclosing those documents, and we intend to send that message [about] how important it is to our national security,” Garland said.