As police put out a renewed appeal, we question whether long ignored patterns of sexual violence raise the possibility of a serial offender and whether Diane’s killer could have been stopped.

We are also reminded that Diane Sindall’s murder is not just about the past as we visit a vigil for victims of violence against women.

Presenter: Olivia Graham.

There’s graphic descriptions of violence in this series. For details of help and support in the UK, visit bbc.co.uk/actionline.

A Geographical Profiler looks at the two locations connected to Diane Sindall’s murder. It’s suggested that Diane’s killer was local and may have struck before.

As new testimony suggests Diane may not have been attacked in the alleyway and emerging accounts name a local figure, the investigation edges closer to a new suspect.

Presenter: Olivia Graham.

There’s graphic descriptions of violence in this series. For details of help and support in the UK, visit bbc.co.uk/actionline.

Returning to Birkenhead in the wake of Peter Sullivan’s release, we focus on Diane Sindall and the community still living with her murder.

Peter shares details of his arrest, interviews and alleged police pressure, alongside renewed police enquiries that revisit overlooked witnesses and potential suspects.

As officers collect fresh DNA and old memories resurface, the search begins anew for the man known only as 'Unknown Male One'.

Presenter: Olivia Graham.

There’s graphic descriptions of violence in this series. For details of help and support in the UK, visit bbc.co.uk/actionline.

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.

There’s graphic descriptions of violence in this series. For details of help and support in the UK, visit bbc.co.uk/actionline.

Years after Peter Sullivan’s conviction, community whispers claim the police convicted the wrong man.

Peter refuses to admit guilt and as advances in DNA testing offer a possible breakthrough for him. His legal team battle missing records, discredited forensic methods and a system reisitant to reopening old wounds.

Until one crucial test changes everything.

Presenter: Olivia Graham.

There’s graphic descriptions of violence in this series. For details of help and support in the UK, visit bbc.co.uk/actionline.

Diane Sindall’s murder ignites a movement with women across Birkenhead. Fueled by anger and grief they challenge police attitudes, confront society’s view of women and demand change.

Against this backdrop Peter Sullivan stands trial. We examine the case built against him with contested confessions, disputed forensic evidence and testimony the jury never heard.

Presenter: Olivia Graham.

There’s graphic descriptions of violence in this series. For details of help and support in the UK, visit bbc.co.uk/actionline.

The hunt for Diane Sindall’s killer uncovers another victim who was dressed in yellow and attacked near the scene on the same night, raising fears of a serial attacker in Birkenhead.

A police appeal focuses on the mysterious “woman in yellow”. As the investigation continues, the police uncover more attacks on women in the area and frustrations grow as leads collapse.

Meanwhile, details of Diane’s injuries intensifies public fear and puts pressure on the police to find an answer.

Presenter: Olivia Graham.

There’s graphic descriptions of violence in this series. For details of help and support in the UK, visit bbc.co.uk/actionline.

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.

There’s graphic descriptions of violence in this series. For details of help and support in the UK, visit bbc.co.uk/actionline.

The murder of Diane Sindall in Birkenhead, Merseyside led to Britain’s longest miscarriage of justice when local man Peter Sullivan's conviction collapsed after 38 years.

This series returns to the streets, alleyways and estates of Birkenhead where it all happened, retracing Diane’s final movements.

Follow through eyewitness testimony, unheard accounts and modern forensic science as we uncover how a brutal crime in a public place went unsolved for decades, while a killer may still be alive and closer to home than anyone realised.

At the heart of this story is Diane: who she was, how violence against women shaped the investigation and what justice really looks like when a community has lived with fear, silence and unanswered questions for generations.

Presenter: Olivia Graham.

There’s graphic descriptions of violence in this series. For details of help and support in the UK, visit bbc.co.uk/actionline.

With the crime apparently solved, one unanswered question continues to hang over the village - and everyone connected to the case - a quarter of a century on.

Presenter: Meic Parry

An Overcoat Media production for BBC Sounds