Significant advances in DNA technology and other cases around the UK suggest the killer could still be brought to justice.
While not involved in the Saunders investigation, the Criminal Cases Review Commission, external looks at miscarriages of justice.
It set up the Forensic Opportunities Programme in 2024 to re-examine closed murder or rape cases from before 2016 where the culprit has not been found.
“Our purpose is to find, investigate and refer potential miscarriages of justice, so it is imperative that we take advantage of opportunities offered by scientific developments to do that,” a spokesperson added.
A cigarette butt recently helped Scottish police to solve one brutal murder dating back to 1984.
Mary McLaughlin, who was 58, was found dead in her flat in Glasgow, in a scene detectives called “particularly cruel”.
It wasn’t until 2021 that her killer was brought to justice after the cigarette stub recovered from her flat proved crucial.
There is also what was previously described as “the UK’s oldest cold case”, which took almost six decades to solve.
The murder of 75-year-old Louisa Dunne in 1967 horrified her community and sparked a manhunt for her killer that saw palm prints taken from almost every man in Easton, Bristol.
Ryland Headley, who is now 93, was caught decades later through DNA and last year was sent to prison.
Police think Saunders’ killer could still be out there, and O’Brien remains hopeful that the case can now be solved.
“Because I met the victim’s family and I’ve seen the pain they were going through, to get justice for them would be amazing, more so for them than myself,” he added.