Diane, 21, was found dead in an alley off Borough Road in Birkenhead, Merseyside, in the early hours of Saturday 2 August 1986. She had been sexually assaulted and suffered extensive injuries, with her cause of death recorded as a cerebral haemorrhage.
Peter Sullivan, then 30, was convicted of her murder in 1987 and earned grim nicknames such as “The Mersey Ripper” and “The Beast of Birkenhead.” He maintained his innocence for decades. In 2025, his conviction was quashed after DNA evidence proved the real killer was someone else. Sullivan’s 38 years behind bars now stand as the longest miscarriage of justice in UK history.
Police are continuing their work to identify the person whose DNA was found at the scene and are appealing for public assistance. Crimestoppers has pledged a reward of up to £20,000 for information leading to the arrest and conviction of Diane’s killer.
Detective Superintendent Rachel Wilson said: “It is devastating for Diane’s family that they are still waiting for answers. We remain committed to identifying the person whose DNA was left at the scene. Although nearly 40 years have passed, we believe there are people who know something and have not yet come forward. It is never too late to do the right thing.”
At the time of her death, Diane had been working part-time at the Wellington pub in Bebington and left at 11.45pm in her blue Fiat van. On her way home, the van ran out of petrol, and she was last seen walking along Borough Road between midnight and 12.20am. Her body was discovered around 12 hours later.
Investigators have also focused on Bidston Hill, where Diane’s property was recovered on 17 August 1986. Witnesses reported seeing a small fire and a man fleeing the scene the previous day.
Police are asking anyone who was on Borough Road on the night of 1–2 August 1986, or who may recognise the man seen running from Bidston Hill, to come forward. DNA samples can be requested from suspects or relatives if necessary.
The £20,000 reward will remain available until 22 April 2026.
