Massachusetts Air National Guard member Jack Teixeira was indicted by a federal grand jury in Boston on Thursday for allegedly leaking highly classified materials on social media, according to the Justice Department. “The unauthorized removal, retention and transmission of classified information jeopardizes our nation’s security,” Acting United States Attorney Joshua S. Levy said in a statement announcing the indictment. “Individuals granted access to classified materials have a fundamental duty to safeguard the information for the safety of the United States, our active service members, its citizens and its allies.” Mr Teixeira is charged with retention and transmission of national defense information and unauthorized removal and retention of classified documents or materials. The Massachusetts man, 21, could face a sentence of 10 years in prison and a fine of $250,000 if convicted. Mr Teixeira, who allegedly posted defence documents on a server within the gamer-focused chat app Discord, has pleaded not guilty. According to prosecutors, the guardsman was warned multiple times by superiors about his “concerning actions” regarding viewing and handling classified information. “The Defendant even continued to share information with his online associates, defying these admonishments and taking further efforts to conceal his unlawful conduct,” officials wrote in a May filing. The guardsman had top-secret security clearance. Armed FBI officials raided Mr Teixeira’s home in April and arrested him. Officials found a collection of weapons including hanguns, bolt-action rifles, shotguns, and an “AK-style high-capacity weapon” in his room. Mr Teixeira was allegedly behind one of the largest intelligence leaks of the decade, and the materials he shared online contained sensitive information about the Russian invasion of Ukraine, Ukraine’s air defences, and the ways the US spies on its partners and allies, according to The Washington Post. On Discord, Mr Teixeira, a cyber transport systems journeyman responsible for communications networks in the Air Force, posted under the screen names “jackthedripper” and “excalibureffect.” One member of the “Thug Shaker Central” Discord server at the centre of the leaks told the Post Mr Teixeira once shared a video of himself shouting racist and antisemitic slurs before firing a rifle. Read More How was a 21-year-old gamer able to leak a mountain of major Pentagon secrets? Guardsman indicted on charges of disclosing classified national defense information Documents leak suspect had been warned about handling of classified information, prosecutors say