Brandy Mulligan is a teenaged girl who is a student in six-form at Rathborne High School. She is the blond, pretty and popular it girl of the school. Her surname was originally Crompton but she changed it at some point due to the Crompton family history of criminal and psychotic behaviour.
Brandy comes across as a Unnervingly sweet popular girl to her fellow students who will make the occasional degrading comments to the unpopular kids like Christa Stammers, whose clothing choices she insults during a conversion.
During the groups investigation into Matt's death, Brandy becomes a suspect after they find out that Matt was perving on the girls locker room whilst they were getting changed. Matt was discovered and Brandy chased him down, and becomes a suspect after they find out her family history.