A 21-year-old member of the U.S. Air National Guard accused of leaking top secret military intelligence records online was charged on Friday with unlawfully copying and transmitting classified material.

Jack Teixeira of North Dighton, Massachusetts, who was arrested by heavily armed FBI agents at his home on Thursday, made his initial appearance in a crowded federal court wearing a brown khaki jumpsuit.

At the hearing, Boston's top federal national security prosecutor, Nadine Pellegrini, requested that Teixeira be detained pending trial, and a detention hearing was set for Wednesday.