Books and Authors: Sunil Gupta, Sunetra Choudhury on Black Warrant: Confessions of a Tihar Jailer

What is it like to witness a hanging? Was Ram Singh, one of the accused in the Nirbhaya case, murdered in prison? What were Afzal Guru's last moments like? Sunil Gupta, who worked at Tihar for 35 years, and journalist Sunetra Choudhury, who helped him put down his story, talk about their sensational book, Black Warrant.