Steve Murphy is the younger brother of Shaun Murphy. He died while they were both young.
Steve was protective of Shaun, and seemed to be the most at ease with Shaun's autism and was better able to communicate with him. When their father killed Shaun's rabbit, Steve spent most of the night in a rain storm searching for a place to help the rabbit. Later, Steve moved with Shaun to an abandoned breakers yard to live there and avoid their father. Steve organized an event with other children so that Shaun could make friends while playing hide and seek with the other kids. While they were walking on top of a train, Steve tripped, fell off, and died. This tragic event served as a catalyst for Shaun to pursue a career in medicine.