Go to the level where you save the marines. Get the sniper. At the bridge, kill the snipers and zoom up by the blue lights. There is a picture of aAbraham Lincoln.
Inside the Atlantis, to the left of the hallway leading to the cockpit, there is a pile of boxes. Directly above this pile, hidden behind the ceiling panel, is a glowing face with glasses and non-glowing eyes. On closer inspection it's guy with a beard,... more
On the level 'Hell - Desolation', after you have been introduced to the 'pods', before the cutseen 'Hell, is this where they are all coming from?...' you get to a place where you climb up a flight of stairs with some ammo underneath on some big blue crates.