WASHINGTON (AP) — A federal judge on Wednesday directed a Libyan militant charged in the 2012 Benghazi attacks to remain in U.S. custody after his own lawyer conceded that he had no reasonable chance of being released.

A lawyer for Ahmed Abu Khattala acknowledged that it was appropriate for her client to remain behind bars at the moment, given the nature of the charge he faces and his lack of ties to the United States. 

But she said she had so far seen no evidence of any role by Khattala in the Sept. 11, 2012 attacks that killed the U.S. ambassador to Libya and three other Americans.

“What’s been filed has shown, quite frankly, an utter lack of evidence of Mr. Khattala’s involvement in the incident in Benghazi,” said Michelle Peterson, an assistant federal public defender, adding, “We are left to glean from press reports what the government’s evidence is.”

Prosecutors provided some new details in a court filing Tuesday night, arguing that he was part of a group of roughly 20 militants who stormed the diplomatic compound on the night of the attacks. They say he was motivated to participate in the attacks by an extremist ideology.

Abu Khattala appeared briefly in federal court in Washington, wearing a green prison jumpsuit and a long, graying beard. He listened to the proceedings through headphones as an interpreter translated the conversation into Arabic. Peterson requested that he be served a halal diet and be provided with a copy of the Quran.

Abu Khattala was captured in Libya more than two weeks ago and then brought to the United States aboard a Navy ship, where he was interrogated by federal agents. He has pleaded not guilty to a charge of conspiring to provide support to terrorists — a crime punishable by up to life in prison — but the Justice Department has said it expects additional charges soon.