The Scared Guard is enountered on Chapter 7: Everything beautiful is gone of The Suffering. He is scared out of his mind when you first meet him, in a cutscene where he sees you, screams and closes a door, and will run from you. When you follow him, he will cower for a minute but realise that Tourque isn't a monster and follow him. From there, you escort him down a walkway and fight off slayers by burning them with spotlights, and along the way, he tells you how his mother predicted this and believes god is responsible for this. He even mentions the title of the chapter: Everything beautiful is gone.
Then, after fighting through a baseball field, you reach the radio tower where he decides to stay. On a later level, one can find his body on the floor with a broken ladder on top of him.
For good morality, escort the guard to the radio building and keep him alive. He will die later on upon returning to the radio building, but that doesn't affect morality.
For bad morality, simply kill him.