Red Sam; Flyleaf and Flannery O'Conner?

So I recently read the short story "A Good Man is Hard to Find" by Flannery O'Conner. One of the characters is named Red Sammy. There's also a song called Red Sam by Flyleaf. Both are Christianity related, so obviously this can't be a coincidence. Does anyone know what or who 'Red Sam' is, or what is means?