Dexter Gibson was chosen to play Derick because he has experience in stage productions and currently plays a main role in the school's production of Singin' in the Rain, making him a competent actor for the role. Jonty Preston was selected as Sir due to his height of 6ft 5in, which will allow him to appear intimidating when interrogating Derick but his size won't always work against the role. Mathew Davies was cast as Man 1 because his tall stature will make him look intimidating.