The suspect in the leak of classified Pentagon documents posted on social media has been charged under the Espionage Act with unauthorized retention and transmission of national defense information and unauthorized removal of classified information and defense materials. Jack Teixeira, a 21-year-old airman with the Massachusetts Air National Guard, made his first appearance in federal court in Boston Friday morning following his arrest by the FBI in North Dighton, Massachusetts, on Thursday. According to charging documents, Teixeira held a top secret security clearance and allegedly began posting information about the documents online around December 2022, and photos of documents in January. Teixeira’s arrest came a week after the initial public disclosure that the classified material had been posted online to a small Discord group, a social media platform popular with gamers. The documents, some of which have been reviewed by CNN, included a wide range of highly classified information, including eavesdropping on key allies and adversaries and blunt assessments on the state of the Ukraine war. Teixeira is believed to be the head of an obscure invite-only Discord chatroom called Thug Shaker Central, multiple US officials told CNN, where information from the classified documents was first posted months ago. Magistrate Judge David Hennessy informed Teixeira of the charges he’s facing and scheduled a detention hearing for Teixeira on Wednesday. He will remain detained until then. Teixeira did not enter a formal plea. Teixeira entered the courtroom wearing a tan shirt and pants from the detention center, as well as hiking boots. He entered the courtroom in shackles, though his hands were uncuffed before he sat down at the defense table. The Boston courtroom was full, including three people sitting on a bench reserved for family. When Teixeira entered the courtroom, he did not look at his family members. Teixeira spoke quietly during the hearing, whispering “yes” as the judge informed him of his rights as a criminal defendant. As the hearing ended, a man in the courtroom shouted, “Love you, Jack.” Teixeira did not look back, but responded, “you too, Dad.” Top secret clearance since 2021 Teixeira has held a Top Secret clearance since 2021, according to the affidavit unsealed Friday. He also “maintained sensitive compartmented access (SCI) to other highly classified programs,” the affidavit says. Many of the leaked documents posted on the online server Discord were marked Top Secret. At least one of the documents he allegedly posted was accessible to him by virtue of his employment with the Air National Guard, the affidavit says. According to a user of the Discord served interviewed by the FBI, Teixeira began posting information in December 2022, according to the affidavit, and began posting photos of documents around January 2023. The unnamed individual who spoke to the FBI said that Teixeira told him that he was concerned about making the transcription at work so “he began taking the documents to his residence and photographing them.” Teixeira also allegedly searched a classified government database for the word “leak” on April 6, when reports began emerging publicly of classified information being posted online. “Accordingly, there is reason to believe that TEIXEIRA 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, to include the Government Document,” the affidavit says. Investigators narrowed in on the potential members of the chat group with evidence collected following the discovery of the classified documents online. Teixeira was under surveillance for at least a couple of days prior to his arrest by the FBI on Thursday, according to a US government source familiar with the case. Four Discord users active in a different Discord chatroom where the documents later appeared told CNN the documents began circulating on Thug Shaker. Another user who was in the Thug Shaker chatroom told CNN they saw the original posts of classified documents but declined to speak further about them. Discord, which is not named in the affidavit but was previously identified by CNN, gave the FBI information on Wednesday about the account that had allegedly been posting the documents. Teixeira used his real name and home address in North Dighton, Massachusetts, for the billing information associated with his Discord account, the affidavit says. Worked in IT in Air National Guard Teixeira was an Airman First Class in the Massachusetts Air National Guard, where he worked as a low-ranking IT official. In his role as a Cyber Transport Systems journeyman, Teixeria would have been working on a network that carried highly classified information, according to a defense official, which is why he needed a security clearance. Several former high school classmates of Teixeira’s told CNN Thursday that he had a fascination with the military, guns and war. He would sometimes wear camouflage to school, carried a “dictionary-sized book on guns,” and behaved in a way that made some fellow students feel uneasy. “A lot of people were wary of him,” said Brooke Cleathero, who attended middle school and high school with Teixeira. “He was more of a loner, and having a fascination with war and guns made him off-putting to a lot of people.” Teixeira grew up in the suburbs of Providence, Rhode Island, according to public records. He attended Dighton-Rehoboth High School where he graduated in 2020, according to the superintendent of the regional school district. Teixeira didn’t behave in a manner that rose to the level where “people felt the need to report him,” another former classmate said, but “he made me nervous.” The same student said she took his fascination with the military as a form of American nationalism, and was therefore surprised by the allegations against him. “I didn’t think he would be capable of doing something like this,” she said. Fallout of leaks continues Defense Secretary Lloyd Austin said Thursday that he is directing a review of intelligence access following Teixeira’s arrest. The Pentagon is still conducting a damage assessment of the disclosure of the classified material, which could be used as evidence against Teixeira. President Joe Biden said Friday that he has discussed the investigation with Pentagon officials and doesn’t think it will take very long, though he declined to say exactly how long the probe might take. “Yes, I’ve instructed the department to make sure that they get to the root of why he had access in the first place, number one,” Biden said. “And number two, to focus extensively on the extent to which it all occurred, and that’s going on right now. I have nothing to report beyond what’s already been reported.” Biden released a statement earlier Friday commending law enforcement for the arrest, and saying: “While we are still determining the validity of those documents, I have directed our military and intelligence community to take steps to further secure and limit distribution of sensitive information, and our national security team is closely coordinating with our partners and allies,” Biden said. Biden had been briefed regularly on the investigation as it proceeded over the past week, according to a US official. He was also briefed regularly on the efforts by his top officials to engage with allies who have been identified within, or unsettled by, the content of the leaked information, one official said. Before the arrest on Thursday, Biden downplayed the impact of the leaked documents. “I’m concerned that it happened, but there is nothing contemporaneous that I’m aware of that is of great consequence,” he told reporters. This story has been updated with additional developments.