Security officer reveals horror of Benghazi attack   Donning gray pants, an untucked white button-down shirt and long gray beard, Ahmed Abu Khatallah silently took notes and sipped water inside a packed Washington courtroom on Monday as prosecutors outlined a case that will attempt to paint him as the ringleader of the 2012 terrorist attack on the US mission in Benghazi, Libya that killed Ambassador Chris Stevens and three other Americans.