Crazy Colin is the brother of Terry Thorpe, the character from the first DLC pack GTA IV: The Lost and Damned. There are a few mentions about him during the friendship activities dialogues. It seems that Jim Fitzgerald knows Terry's brother and knows that he's insane. Terry and Colin's father didn't want to see Jim in their family's farm, leading to Crazy Colin becoming a man of God. Some time after this, he began using drugs and became a heroin addict.