James was extremely angry that that thug Mad Dog shot J.J. and wanted to even up the score. He and Florida had several arguments throughout this episode because James kept ignoring Florida's repeated urgings to forgive and forget, since Mad Dog was in custody and waiting for the law to handle the situation. James can hardly be blamed for his vengeful tactics but needed to realize that the law didn't recognize his eye for an eye philosophy.
Mad Dog showed no remorse during the hearing, acted very smug and disrespectful, pled guilty and threw himself at the mercy of the court. The judge had no choice but to place him on probation due to overcrowding at the reformatory and the state penetentiary, as well as Mad Dog's juvenile age preventing him from serving at such a place.
Just as the audience was to shriek in disgust over Mad dog's lenient sentence, his mother told him she no longer loved him and was disowning him, because he was such a bad egg. James decided to let Mad Dog go out of pity when he realized mad dog was bitter about his father leaving him as a young child.