• 
  Barbara Flynn

  Self - Narrator
• 
  Caroline Catz

   Herself - Narrator (10 episodes, 2013-2014)
• 
  Alex Iszatt

  Self - Behavioural criminologist
• 
  Vaani K Sharma

  Jessica Patel
• 
  David Holmes

  Self - Criminal Psychologist
• 
  Paul Cheston

  Self - Evening Standard
• 
  David Wilson

  Self - Criminologist, Birmingham City University
• 
  Stephen James Adams

  Dennis Nilsen

• 
  Ioan Davies

  Narrator
• 
  Tommy Alexander

  Jeremy Bamber
• 
  Imogen Slaughter

  Jane Andrews
• 
  Mike T. Smith

  Jonathan Vass
• 
  Harry Willis

  Reenactment Cast
• 
  Helen Cashin

  Stacey Mackie
• 
  Rachel Chambers

  Sam Greening

• 
  Olivia Jewson

  Lorraine Thorpe
• 
  Marie Taylor

  Rebecca Thorpe
• 
  Vince Egan

  Self - Forensic Psychologist, University of Leicester