Sunil Gupta is the co-author (with Sunetra Choudhury) of Black Warrant: Confessions of a Tihar Jailer (2019). He began working at Tihar Jail in 1981 and was later promoted as the spokesperson and legal advisor of the jail. After leaving Tihar Jail, he has worked with the High Court and Supreme Court as an advocate and member of the Delhi High Court Bar Association. His efforts to improve India’s prison systems have earned him the India Vision Award in the field of Prison Reforms and Administration. He is the only legal officer to receive the President’s Correctional Medal for Meritorious as well as Distinguished Services.