Air National Guardsman Jack Douglas Teixeira, 21, has been named as the suspect at the centre of the leak that has upset the US and its allies
Mr Teixeira only graduated in 2020 from high school in his hometown of North Dighton, Massachusetts.
A year earlier he enlisted in the Massachusetts Air National Guard – which is a reserve of the US Air Force – joining the 102nd Intelligence Wing.
Mr Teixeira was promoted last July to Airman 1st Class – a relatively junior position – and was based at Otis Air National Guard Base in western Cape Cod.
According to his service record, his official title is Cyber Transport Systems journeyman.
The Air Force’s official website notes that personnel assigned to Cyber Transport Systems jobs are responsible for operating the Air Force’s global communications network.
Mr Teixeira’s record does not suggest any overseas deployment.
His family reportedly has a history of military service. His stepfather retired after 34 years of service, according to the Washington Post. His last posting was as a master sergeant from Mr Teixeira’s unit, the 102nd Intelligence Wing.
His mother has previously worked in non-profits focused on veterans, as well as the Massachusetts Department of Veterans Services, according to LinkedIn and public records cited by US media outlets.
She posted photos of the family every year for Veterans Day. Other photos on social media reportedly show Mr Teixeira with his family’s two dogs and riding all-terrain vehicles.
He was reportedly known as the leader of an invitation-only Discord chatroom created in 2020.
Thug Shaker Central included roughly 20 to 30 members – mostly young men – from various countries.
The Washington Post reported that the group had swapped “memes, offensive jokes and idle chitchat”, watched films together and prayed.
A member of the chatroom said Mr Teixeira was a young, charismatic gun enthusiast.
Other members told US media that Mr Teixeira was older than most in the group and appeared keen to impress them.
One told the New York Times: “He was the man, the myth. And he was the legend. Everyone respected this guy.”
According to the Post, Mr Teixeira told the group he worked in a facility where phones were banned.
He reportedly used various usernames online, such as TheExcaliburEffect, jackdjdtex and TexKilledYou.
He previously wrote up versions of the sensitive information and shared it to the chatroom.
But he reportedly began sharing photos of the files after becoming frustrated when other members of the chatroom did not pay attention.
On one occasion, the Post reported, he sent an irate message to the group complaining that they were more interested in YouTube videos.
“He got upset, and he said on multiple occasions, if you guys aren’t going to interact with them [the files], I’m going to stop sending them,” the unidentified group member told the newspaper.
One teenager in the group had a theory on why Mr Teixeira shared the documents.
“This guy was a Christian, anti-war, just wanted to inform some of his friends about what’s going on,” he told The New York Times.