From WikiGTA - The Complete Grand Theft Auto Walkthrough
|Gang||Grove Street Families|
|GTA||GTA San Andreas|
Brian Johnson is the younger brother of Carl, Kendl and Sweet. He died in 1987, after which Carl left Los Santos and went to Liberty City. We don't know that much about Brian. One of the photographs in the Johnson House could be of him, but we can't be sure. His existence however is very important for the game, because that was the reason Carl left Los Santos and returns to correct things for his family.