Police have launched a review into the unsolved murder of a 76-year-old Arthur Brumhill whose body was found at a pet shop in 1993.
The pensioner was found dead in the basement of the pet and garden shop where he worked after being attacked on the evening of January 21 1993.
A small amount of cash and a tyre lever were taken from the premises in Wellingborough Road, Northampton.
Although the murder has been subject to regular police reviews during the past two decades, advances in forensic techniques have resulted in a reassessment of the evidence.
Detective Inspector Louise Hemingway, of the East Midlands Special Operations Unit, confirmed that the latest review had seen a number of items submitted for further examination.
She said: "Unfortunately not every murder is immediately solvable, but our commitment to bringing the offender to justice remains as strong as it did 20 years ago.
"We never forget that behind every murder there is a family who continue to live with the trauma and pain such a death brings.
"Sadly, with Arthur's case remaining unsolved, his family have not had the opportunities to find the closure that most other families have.
"Along with Arthur's family, we are appealing for anyone with any information to come forward so this case can be solved."
In a statement issued by police, the victim's daughter, Sue Blake, said: "Though my father was murdered 20 years ago, not a day goes by when I don't think of him and of the brutal way his life was ended.
"If anybody has any information they have been withholding over the past two decades for whatever reason, please, please come forward.
"It could be the missing piece of the jigsaw the police need, so that as a family we can at last have some closure."