Paranoid Marine

=Halo: Combat Evolved= This UNSC Marine was presumably a member of Fire Team Charlie, deployed to what was thought to be a Covenant weapons cache. In reality the fire team was headed for a Flood Containment Facility.

He was inserted into the swamp by Pelican Victor 933, along with Sergeant Johnson, Private Bisenti, Private Mendoza, and Private Jenkins. The squad met up with Captain Keyes, along with Privates Kappus and Riley, after discovering the remains of a dead Elite. After entering a large hall, the squad was ambushed and attacked by small, squidlike creatures. This Marine witnessed the death of almost his entire unit, and fled the battle.

Long after the Flood had finished their massacre of Marines and Covenant alike, Spartan-117 came across this Marine. The soldier was a wreck, firing at anything that moved with his pistol, and hollering about "monsters." It was once unknown what happened to the Marine but further inspection revealed his dead body near a pile of rubble. It is unknown why he remained un-infected but some think he killed himself.

Finding his Body
It's possible to see his dead body after the flood outbreak. To do so you must get to the part were the Flood attack without killing the marine. Backtrack to where he was and you'll find his body in a pile of rubble surrounded by blood. It is unknown if he killed himself or if he was killed by the flood and was not infected.

=Halo 3=

A marine with an identical voice and mannerisms can be found on Earth in the Halo 3 Campaign level Floodgate. He was likely part of the large Marine force that assaulted Voi. When the Flood arrived and began infesting the city, his comrades were infected by the Flood. He killed them with his pistol before they could become combat forms. When the Master Chief and the Arbiter arrived at his location, he was huddled in a fetal position, babbling about how he had no choice but to kill them, and how the Flood "talked to him" through their infected bodies. The marine constantly points his sidearm at his temple, probably tempted to commit suicide.

Whether this marine is intended to be the same character as his counterpart from the first game is unknown, though doubtful.

On Jenkins's helmet recording, a fourth unnamed Marine besides Johnson, Jenkins, Mendoza, and Bisenti can be seen on the dropship. During the Flood ambush, Keyes can be heard yelling at a Marine "Get back here Marine, that's an order!" It can be presumed that this is the Crazed Marine.

343 Guilty Spark (Level) the only appearance of the Crazed Marine. Checkpoint two when John-117 gets inside the containment facility.