Peter Sullivan then aged 30, was branded the “Beast of Birkenhead” when he was jailed for 38 years after being wrongly accused of beating florist Diane Sindall, 21, to death in August 1986
Detectives have DNA tested more than 600 men as they seek to solve a brutal 40-year-old murder for which an innocent man spent 38 years behind bars.
Peter Sullivan, then aged 30, was branded the “Beast of Birkenhead” and “Wolfman” after being wrongly accused of beating florist Diane Sindall, 21, to death in a frenzied sexual attack on August 2, 1986.
His conviction was quashed in May last year after he claimed he made a false confession following abuse by Merseyside officers. Now, ahead of the anniversary of the murder, the force has said they are doing “everything in our powers” to catch the killer.
An investigation into the killing in the Wirral was relaunched in 2023 after DNA tests found a match for a male on samples taken from the scene. Extensive enquiries, including working with the National Crime Agency to identify the person the DNA profile belongs to, remains ongoing.
A Crimestoppers reward of up to £20,000 for information given exclusively to the charity that leads to the arrest and conviction of the person responsible for Diane’s murder remains in place.
Detective Superintendent Rachel Wilson, the officer leading the inquiry, said: “It’s unthinkable that 40 years on from Diane’s murder her killer has still not been brought to justice but I want her family, friends and the wider public to be reassured that we are doing everything in our powers to find that person.
“We have a dedicated investigation team who have been painstakingly reviewing the original investigation, re-interviewing witnesses, carrying out DNA tests and following up new information submitted by the public.
“We remain determined that Diane’s family get the answers they have waited so long for and that we get justice for Diane. Forty years is a long time but it is never too late for someone to do the right thing and come forward with any information they have which may help to assist our enquiries.”
She added: “In 1986 DNA was very much in the early stages and as such was not available to the detectives who originally investigated Diane’s death but her murder was fully investigated by the team.
“We believe the DNA profile will be key to finding the killer and to date have eliminated 575 people and 32 currently under review.
“It is also possible that someone could hold information about the identity of Diane’s killer but either through fear or a misplaced sense of loyalty has not yet come forward. To those people I would say, please have the courage to tell us what you know.”
Diane was working part-time shifts at a pub in Bebington to help raise extra money for her planned wedding the following year. At the end of a Friday shift she set off for home, five miles away in Seacombe, in her blue Fiat van, only to run out of petrol.
She started to walk along a busy, well-lit main road and was spotted by witnesses walking along Borough Road towards Tranmere between midnight and 12.20am.
Twelve hours later Diane’s body was found by a dog walker in an alleyway. She had been beaten to death in a frenzied sex attack. According to police: “She had suffered extensive injuries to her body. Her cause of death was established as a cerebral haemorrhage following multiple blows.”
The murder prompted the biggest manhunt in the history of Merseyside police, with officers speaking to about 3,000 people. On 23 September, Sullivan was arrested after apparently giving police a number of different accounts of his movements.
It was alleged that he had spent the day drinking heavily in a pub 10 minutes from where the body was found. After losing a darts match it was said Sullivan went out armed with a crowbar before what was a chance encounter with Diane.
Sullivan was initially denied legal representation or an appropriate adult in police interview, on the grounds that officers were concerned that sensitive information might be leaked about the investigation.
His trial in 1987 heard evidence from dental experts that bite marks on Diane’s body could be matched to Mr Sullivan’s teeth, leading to the ‘Wolfman’ nickname.
The DNA sample that secured his release was only made possible by a method that first came into use in 2015.
Speaking after his release Sullivan said: “I feel sorry for (Diane’s family), I really do feel sorry for them and what they’re going through at the moment, where they’re back at square one and not knowing who the person is that killed their daughter.
“I don’t know what to say to them, I am really sorry for what’s happened to their daughter, and if they need – if they want – my support when they go to court with the guy, when they find him, I will go to court with them, I will be there by their side 100%, because I will be there for them.”
