Anti-nuclear campaigner Hilda Murrell died after being sexually assaulted and stabbed in 1984.
Her murder remained unsolved for 21 years, until builder's labourer Andrew George was convicted of killing the 78-year-old, whose body was found in a copse in the shadow of Haughmond Hill, three days after being abducted from her home.
In 2005 George, who was then 37, was given a life sentence for his crimes, and was told it would be at least 15 years before he could be considered for parole.
He had admitted being present at Miss Murrell's home as a 16-year-old, but had insisted he was not responsible for killing her.
It has now been revealed that the parole board held a hearing to consider whether George should be eligible for release – or moved to an open prison.
Listing its findings the board said that while George's behaviour in prison had "been better recently", no witnesses could support his release.
A report said: "Evidence was presented at the hearing regarding Mr George’s progress and custodial conduct during this sentence.
"His behaviour had been better recently and witnesses spoke about his much improved stability.
"Mr George had undertaken accredited programmes to address decision making, sex offending, and better ways of thinking.
"None of the witnesses could support his release or his progression to open conditions at this point, but specialised prison regimes and therapies could be available as a next step."
The board concluded that the level of risk posed by George meant he could not be transferred to open prison.
It said: "After considering the circumstances of his offending, the progress made while in custody and the evidence presented at the hearing, the panel was not satisfied that Mr George was suitable for release.
"Nor did the panel recommend to the Secretary of State that Mr George should be transferred to open prison.
"Given that areas of treatment and therapy were likely to be needed, the panel considered that Mr George was appropriately located in custody where outstanding levels of risk could be addressed.
"He was assessed as not meeting the criteria for recommending transfer to open prison at this stage."
The panel said George "will be eligible for another parole review in due course".
The review was George's second since his conviction.