A man has been arrested over the "brutal" stabbing of an 83-year-old dog walker.
More than 100 police officers joined an investigation after Peter Wrighton's body was found in woodland in Norfolk.
A Home Office post mortem examination concluded Mr Wrighton died as a result of multiple stab wounds to his neck and head.
Detectives investigating the "horrendous" murder said they would re-close The Street, close to where Mr Wrighton was found, later today for "operational reasons".
"My thoughts are with the victim's family and friends at this devastating time".
DS Andy Smith, from Norfolk Police, said they have not been declared suspects and are people officers have not been able to trace, yet might have vital information.
They asking people who live within a five mile radius of the crime scene to check their bins for "a weapon or anything unusual", as a weapon is yet to be discovered.
His death was initially treated as unexplained with an "animal attack" considered as one of the possible explanations.
Police confirmed a witness reported hearing two elderly men having a bust-up in the woods around the time the pensioner was murdered.
His body was found by a member of the public at 10.46am.
A FORMER BT worker murdered while walking his dogs was a "lovely gentle husband, dad and grandfather".
The first is described as a slim white male over 50, with pale skin and grey or white hair and balding on top.
He wore a grey or blue t-shirt, grey floppy gym-style shorts above the knee and heavy duty flip flops, and was seen within the boundary of the woodland site which police are searching.
The third is a white male, of medium build, who was wearing dark coloured clothing.
Anyone with information is asked to contact police on 0800 056 0944 or 0207 158 0010, quoting Operation Graduate.