Diane Sindall, 25, finished her shift at the Wellington pub just before midnight on August 1, 1986, when her blue van ran out of petrol. Her partially clothed body was found by a dogwalker in an alley off Borough Road the next day. Sullivan was convicted but maintained his innocence. In May 2024, DNA evidence showed the killer's DNA did not match Sullivan's, leading to his release.
An ex-Merseyside Police officer has now come forward, claiming two senior detectives told him not to investigate despite his concerns about a pattern of sex attacks before Sindall's murder. According to Daily Mirror - Main, the ex-officer described how he first encountered the cases after being asked to investigate a sexual assault on Borough Road in July 1986. He saw a pattern of attacks in the same area with a similar modus operandi suggesting one attacker. He requested case files for similar offences but was allegedly blocked. The ex-officer discussed his concerns for a BBC podcast 'Crime Next Door: The Beast of Birkenhead'.
Merseyside Police said there was currently no evidence linking Ms Sindall's murder to the other offences. It remains unclear what specific evidence, if any, links the other sex attacks to each other or to Sindall's murder, and why the senior detectives allegedly told the ex-officer not to investigate.