A US federal judge on Wednesday ordered the suspected ringleader of the deadly 2012 attack on the US mission in the Libyan city of Benghazi held without bail until his trial on terror-related charges. Judge Deborah Robinson sided with federal prosecutors, who argued that Ahmed Abu Khatallah posed a "serious danger to others" and was a clear flight risk because he has ** ties to the United States. Assistant US Attorney Michael DiLorenzo also emphasized that the "seriousness of the offense" allegedly committed by the Libyan national necessitated keeping him behind bars. Abu Khatallah, who was captured last month by US commandos in Libya, has been charged with conspiracy to provide material support and resources to terrorists resulting in death -- that of US ambassador Chris Stevens and three other Americans.