Have you considered going to his mother for custody? Sounds like she and your brother were never married. In NC as in many states sole custody goes to the mother until the child is legitimized by the father by either marrying the mother or filing for legitimization through the courts.
Something is not sounding right here to me. 4 DUI's and you are having problems trying to get custody? I think I would look into another lawyer they are not all created equally. Perhaps if he goes to jail today you might go the route of his mother.