U.S. Federal Marshals patrol outside the U.S. federal courthouse in Washington June 28, 2014. Ahmed Abu Khatallah, the Libyan militia leader suspected in the 2012 attack on the U.S. diplomatic mission in Benghazi that killed four Americans, was in federal custody on Saturday morning, according to the spokesman for the U.S. attorney's office for the District of Columbia Bill Miller. Miller would not comment on where Khatallah was being held, but there was there was heightened security around the federal courthouse building. REUTERS/Jonathan Ernst (UNITED STATES - Tags: POLITICS CRIME LAW)