1. The Murder

In 1986, Diane Sindall leaves work to drive home but never arrives. What happened that night marks the start of a decades long unsolved case.

Through testimony from those who knew her and those who encountered the crime scene, we look at Diane’s final movements, the violent nature of her attack and the growing fear gripping Birkenhead, a town on the Wirral in Merseyside.

As we find out more, troubling questions emerge about how such brutality could occur in a public place unseen and unheard, setting the stage for what would become one of Britain’s most haunting criminal cases.

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.