By Antoinette Radford and Chloe KimBBC News

Prosecutors say an American accused of one of the highest-profile intelligence leaks in years had a history of violent threats and troubling social media posts.

Jack Douglas Teixeira, 21, is charged with the unauthorised removal and retention of classified documents and materials. If found guilty, he faces up to 25 years behind bars.

In court papers, government prosecutors disclosed that he was once suspended from secondary school and denied a firearms ID over troubling comments he made.

Authorities further allege he destroyed his electronic devices and other evidence as they closed in on an arrest.

But many questions remain about why Mr Teixeira would share highly sensitive files, including confidential information about the war in Ukraine and other national security issues.

'An ongoing risk to national security'

Mr Teixeira enlisted in the Massachusetts Air National Guard, a reserve of the US Air Force, in 2019. His job title is cyber transport systems journeyman, and he holds the junior rank of Airman 1st Class.

He has top secret security clearance. In order to be given this clearance, Mr Teixeira signed a "lifetime binding non-disclosure agreement" acknowledging that the "unauthorized disclosure of protected information could result in criminal charges", according to court documents.

Personnel assigned to his role are responsible for operating the Air Force's global communications network and require a background check that allows access to top secret information.

But the government has argued Mr Teixeira has a history of extreme remarks and behaviour, and would pose a serious flight risk and ongoing threat of further damage to national security if he was released from jail pre-trial.

Their latest court filings alleged that the airman wrote on social media about how he would kill a "ton of people" if he had his way, and had discussed guns and vehicles he could use to conduct mass shootings.

While still in high school, he was allegedly overheard by a classmate talking about Molotov cocktails and guns and making racial threats. Those comments earned him a suspension and later led to him being denied a firearms identification card, the filing says.

At home, his gun locker sat close to his bed and he owned so many weapons they accounted for about half of his overall net worth, prosecutors said.

And with his arrest imminent, he allegedly smashed his tablet, laptop and Xbox console; encouraged members of the chatroom where he leaked files to delete their messages; and then deleted the chat server itself.

Memes, guns and secret documents

Mr Teixeira allegedly first leaked the files on the online chatroom platform Discord, a popular hangout among gamers.

Known as "OG", he was the administrator of an invitation-only server called Thug Shaker Central, which he created during the height of the coronavirus pandemic in 2020.

The group reportedly had about two dozen members and swapped "memes, offensive jokes and idle chitchat". They also watched films together, discussed their favourite guns, prayed together and messaged extensively about the war in Ukraine.

One member of the chatroom described Mr Teixeira to the Washington Post as a young, charismatic gun enthusiast. Others said he was older than most in the group and appeared keen to impress them.

Before he shared images of US intelligence material in January, Mr Teixeira allegedly 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 with the lack of response.

On several occasions, the Post said, he complained that they were more interested in YouTube videos and he would stop sending documents if the group did not interact with them.

The Post was also shown videos from a member of the group of Mr Teixeira shouting racist and anti-semitic slurs before firing a rifle. He told the group he worked in a facility where phones were banned.

In early March, members of his chatroom began posting the files on other Discord servers, including ones dedicated to the game Minecraft and a Filipino YouTuber.

One member of the group theorised to the New York Times: "This guy was a Christian, anti-war, just wanted to inform some of his friends about what's going on."

More Pentagon leaks coverage:

What family and friends say

Friends of Mr Teixeira have said he is not a whistle-blower and he has long wanted to join the military,

His family has a history of military service. His stepfather retired after 34 years of military service, while his mother previously worked for non-profit organisations focused on veterans, according to LinkedIn and public records cited by US media outlets. The latter posted photos of the family every year for Veterans Day.

Both parents attended Mr Teixeira's court appearance earlier this month, but made no comment to the swarm of media that surrounded them as they left court.

The only time they spoke was when Mr Teixeira's stepfather shouted "I love you, Jack" inside the courtroom. The shackled defendant replied "I love you too, dad".

The family live in North Dighton, Massachusetts, where Mr Teixeira graduated from high school in 2020. He was arrested outside the family's rural home by heavily armed FBI agents on 13 April.

Neighbours described Mr Teixeira as being "big into video games" but a "good kid, not a troublemaker". One former classmate told CNN they "could never have foreseen" his actions.

ncG1vNJzZmivp6x7o67CZ5qopV%2Bjsri%2FjrCmq6SUYsK0ecKapZqckWKDdn6WamptcA%3D%3D