John "Divine G" Whitfield is the real live person Colman Domingo portraits in the movie Sing Sing. He is the founder/owner of Divine G Entertainment, is a novelist, screen writer, playwright, internet radio talk show host, actor and film director and producer.  He is also the winner of several PEN American Center awards and the 2008 Tacenda Literary award for best play. 
Divine G Entertainment is an urban based entertainment company that sales novels in numerous formats, including ebooks, paperbacks, screenplays and audio books, and provides services such as novel editing, adaptation and short film production.