The Beast of Birkenhead: 5. Unknown Male One

Recorded on the day of Peter Sullivan’s appeal as judges consider DNA evidence unavailable in 1987.
As the new evidence points to an unknown male, decades-old evidence crumbles under scrutiny.
The court delivers its decision leaving one devastating truth intact: Diane’s killer has not been found.
Presenter: Olivia Graham.
Producers: Kate Bissell, Gemma Maull and Olivia Graham.
Sound Design and Music Composition: Phil Channell.
Mixing: Ivan Eastley.
Story Consultants: Neil McCarthy, Jack Kibble-White and Kirsty Williams.
Online Producer: Rachael Smith.
Development was by BBC Audio Scotland and BBC Merseyside.
Executive Editors: Gillian Wheelan and Ben Anderson.
Commissioning Editor: Alistair Miskin.
There’s graphic descriptions of violence in this series. For details of help and support in the UK, visit bbc.co.uk/actionline.