Luke Neal Creator, Writer, Executive Producer Lewis Arnold Creator, Director, Executive Producer David Tennant Dennis Nilsen Actor, Executive Producer Daniel Mays DCI Peter Jay Actor Jason Watkins Brian Masters Actor Barry Ward DI Steve McCusker Actor Ron Cook DCS Geoff Chambers Actor Jay Simpson DS Chris Healey Actor Ben Bailey Smith DC Brian Lodge Actor Bronagh Waugh Charlotte Proctor Actor Faye McKeever Linda Jay Actor Jamie Parker Allan Green QC Actor Pip Torrens Ivan Lawrence QC Actor Laurie Kynaston Carl Stottor Actor Ross Anderson Douglas Stewart Actor Chanel Cresswell Lesley Mead Actor Andrew Woodall Professor Hardy Actor Silas Carson Russell Cavendish Actor Oscar Garland Juan Actor Tony Way Mike Cattran Actor David Meanti Producer Willow Grylls Executive Producer Kim Varvell Executive Producer Charles Pattinson Executive Producer Elaine Pyke Executive Producer