The cast and creators behind the Metropolitan Opera production discuss the decision to bring Sister Helen Prejean's memoir to a new stage: Sing Sing Maximum Security Prison. WATCH NIGHTLINE EPISODES: abc.go.com/shows/nightline ALSO AVAILABLE ON HULU: hulu.tv/2wSmSrZ #nightline #deadmanwalking #opera #operahouse #memoire #abcnews #abcnews