A member of the Massachusetts Air National Guard was arrested by the FBI on Thursday in connection with the leaking of classified documents that have been posted online, Attorney General Merrick Garland announced Thursday. (…)

The Joint Staff, which comprises the Defense Department’s most senior uniformed leadership that advises the president, began examining its distribution lists immediately after learning of the trove of leaked classified documents – many of which had markings indicating that they had been produced by the Joint Staff’s intelligence arm, known as the J2.