Martin Clunes
— John George Haigh
Keeley Hawes
— Gillian Rogers
Richard Hope
— Dr. Archie Henderson
Celia Imrie
— Rose Henderson
Rowena Cooper
— Mrs. Durand-Deacon
John Flanagan
— Arnold Burtin
Terence Beesley
— DS Heslin
Matyelok Gibbs
— Mrs Constance Lane
Barbara Marten
— Emily Haigh
Geoff Holman
— John Haigh Senior
Christopher Town
— John George Haigh (as a boy)
Ken Drury
— Mr. Greig
Neil McKinven
— Donald McSwan
Claire Nielson
— Amy McSwan
Donald Douglas
— William McSwan
Christopher Ettridge
— Steven Rogers (as Chris Ettridge)
Sally Carman
— Betty
Duggie Brown
— Morrison
Emma Cooke
— Mrs Louisa Bird
Paula Stockbridge
— Mrs Kirkwood
Amanda Haberland
— Sgt. Lambourne
Charles De'Ath
— Sgt Symes
Geoff Oldham
— Magistrate
Randal Herley
— Elderly Resident
Eamonn Riley
— Mr Parry
Nick Chadwin
— Veterinary Surgeon