A community holds the key to help solve the murder of a man killed in his Essex home four years ago, police believe.
A murder inquiry started after Michael Shipton, known locally as Joe, was found on 25 March 2006 at his house in The Plashets, Sheering, near Harlow.
Mr Shipton, 61, died of head injuries after being struck several times with a blunt instrument.
Essex Police have renewed their appeal for information and issued an artist's impression of the victim.
Det Sgt Ed Mayo said: "Despite the passage of time, we are determined to find who killed Joe Shipton.
"Someone knows who is responsible and I believe that their conscience may be troubling them and so now is the time to contact police or give information anonymously via Crimestoppers."
Betty Taylor, Mr Shipton's sister, said: "Joe is dearly missed by the family and we hope with the passage of time anyone with any information surrounding Joe's murder can now come forward and help the police."
Mr Shipton was murdered between 1630 GMT on Friday 24 March and 1000 GMT the next day.
He was discovered after a concerned friend called at the house, where he lived alone and found him dead.
Police found no evidence that the attacker forced their way in, but are keeping an open mind on whether Mr Shipton knew his killer.
He had been made redundant from his job in the 1970s and did gardening and other odd-jobs for cash.
Detectives started a murder investigation and more than 700 people were interviewed, including all residents in the village of Sheering.
Posters and leaflets were distributed and the murder was featured on BBC Crimewatch.
A reward was offered for information leading to a conviction, however, no one has so far been arrested.