Tom George Director Sam Rockwell Inspector Stoppard Actor Saoirse Ronan Constable Stalker Actor David Oyelowo Mervyn Cocker-Norris Actor Adrien Brody Leo Köpernick Actor Ruth Wilson Petula Spencer Actor Reece Shearsmith John Woolf Actor Harris Dickinson Dickie Attenborough Actor Charlie Cooper Dennis Corrigan Actor Pippa Bennett-Warner Ann Saville Actor Pearl Chanda Sheila Sim Actor Sian Clifford Edana Romney Actor Jacob Fortune-Lloyd Gio Actor Shirley Henderson Dame Actor Mark Chappell Screenwriter Damian Jones Producer Gina Carter Producer Katie Goodson Executive Producer Richard Ruiz Executive Producer Jamie Ramsay Cinematographer Gary Dollner Film Editing Peter Lambert Film Editing Daniel Pemberton Original Music Amanda McArthur Production Design Daniel Kearns Art Director Abbie Bellwood Art Director Celia De La Hey Set Decoration Odile Dicks-Mireaux Costume Design Yesi Ramirez Casting