A friend of the defendant in the Arthur Brumhill trial declined to make a statement after his pal apparently confessed because he believed the admission was said in jest.
Mr Brumhill's body was discovered at the bottom of a stairwell at Paul Denton Pet and Garden Supplies in Wellingborough Road on January 21, 1993 and Stuart Jenkins was arrested in 2015 over his murder.
During evidence in Jenkins' trial yesterday, the defendant's boyhood friend Dean Kirk said Jenkins had said he killed Mr Brumhill. However, believing the admission to have only been said in jest, he only brought it to the attention of police during a chance encounter with a policeman nine months later.
The court heard that, after returning home late on the night of October 18, 1993 after being reported missing by his parents, PC Sean Doyle, a family friend, visited to give the then 13-year-old Mr Kirk words of advice.
Mr Kirk explained that he had been out with Jenkins that evening and told PC Doyle his friend had previously made an admission of murder to him that he believed was made in jest.
PC Doyle made a note of what he was told and submitted an intelligence report at a later date.
The report said: "Stuart changed attitudes and moods recently and keeps saying that he murdered an old man at the pet shop one morning when he broke in to steal some money.
"He said he hit the old man three or four times over the head with something and that he threw it away with his trainers afterwards."
Cross-examining the witness, defence barrister, William Harbage QC asked PC Doyle whether he made a contemporaneous note at the time.
PC Doyle told the court he suffers from dyslexia and he may have submitted the report up to four hours after being told the information.
The court also heard that Mr Kirk later refused to give a further statement to police.
However, in a statement in 2015, after Jenkins' arrest, Mr Kirk said to police: "Stuart told me when we were together that he pushed the owner down the stairs, that being the owner in the pet shop."
In a second statement made later that day he said: "I did not think at the time he was being serious."
Mr Harbage questioned Dean Kirk, suggesting it would be odd for Jenkins to throw away trainers.
He said: "Stuart wasn't very well off back in those day's was he?"
To which Mr Kirk replied: "No, I don't think any of us were."
"Not the type of boy to be throwing trainers away," Mr Harbage added.
The trial continues.