The above is from Mouthpiece's first story, and it is the only introduction creator Fred Guardineer ever gives. Mouthpiece is yet another 1940s, blue suited lawyer tired of the red tape. He stands out from look a likes The Sprit and Midnight because he is played complete straight. His comics are darker, more violent, and generally not as good.
Mouthpeice only lasted until Police Comics #13. In modern times, he has shown up as part of the DC Universe in Dr. Mid-Nite #1. Not as a crime fighter, but as a law advisor to Dr. Mid-Nite who lost his family to AIDS.