The 21-year-old member of the Massachusetts Air National Guard suspected of leaking highly classified US intelligence documents online made his initial appearance before a federal judge in Boston on Friday.

He faces two separate counts according to the Justice Department: The unauthorized retention and transmission of national defense information and the unauthorized removal and retention of classified documents or material.

Jack T. was arrested by federal investigators on Thursday afternoon at his family house in North Dighton, Massachusetts.

He appeared in court in a brown khaki jumpsuit and only spoke twice during the brief proceeding, answering "yes" when asked if he understood his right to remain silent.

At the hearing, Boston's top federal national security prosectuor, Nadine Pellegrini, requested the suspect be detained pending trial.

He did not enter a plea and is detained pending a hearing on Wednesday, April 19.

What to know about the case

The suspect was arrested following a fast-moving investigation related to leaks of intelligence documents in recent weeks.

The documents first leaked in March or perhaps earlier on a chatroom on Discord, a social media platform, where the serviceman is believed to have posted for years about guns, games and his favorite memes. 

But the news of their existence did not come to light until it was reported by the New York Times last week. 

According to some members of the private chat group, Jack T. also posted closely guarded US secrets.

Although a motive is not yet known, accounts of those in the private group depict the suspect as motivated more by bravado than ideology.

How did the suspect get the documents?

The suspect was an IT specialist responsible for military communication networks, including their hubs. In that role, he had a higher level of security clearance.

When asked how such a young service member could have had access to highly sensitive documents, Pentagon spokesman, Brigadier General Patrick Ryder, said it was the nature of the military to trust its very young service members with high responsibility.

US government officials have called for a thorough investigation into how the documents leaked and why it went unnoticed when it first circulated on Discord.

The case underscores the challenges the US and other governments have in keeping secrets given the rapid expansion of global online communication over multiple platforms and as the share of people with internet access and computer literacy rises rapidly around the world.

A serious security breach

The leak has drawn comparisons to previous intelligence disclosures, such as WikiLeaks publishing thousands of classified files in 2010 obtained from a low-ranking military member who received a 35-year jail sentence.

Many of the documents pertain to the war in Ukraine, with some revealing sensitive information about the Ukrainian military capabilities and shortcomings. Some have not been individually authenticated by US officials.

The documents showed the degree to which the US has penetrated the Russian Ministry of Defense and the mercenary Wagner Group.

They detail other information, including the circumstances in which US intelligence believed that Russian leader Vladimir Putin might use nuclear weapons.

Editor's note: DW follows the German press code, which advises us to protect the privacy of suspected criminals or victims in most cases prior to conviction, and recommends we refrain from revealing full names.

rm/msh (Reuters, AP)