A man in his 20s has been arrested on suspicion of murder following the death of a dog walker in Norfolk.
Peter Wrighton, 83, was walking his dogs in woodland near East Harling on 5 August, when he was subjected to a horrifying attack. He suffered multiple stab wounds to his neck and head.
Police released CCTV images of Mr Wrighton in Kenninghall Post Office four miles from the woods, at 10.12am, half an hour before he was murdered. He drove his red Skoda 4.5 miles to The Street, close to the area where he walked his dogs.
Ar 10.46am his body was discovered by a passerby near the Fiveways Junction. His dogs, Dylan and Gemma, were close by.
Over 100 officers are investigating the murder of the grandfather, while search teams have been using metal detectors and dogs to look for evidence from the scene of the attack BBC News reports.
Following a public appeal, 220 people called Norfolk Police with information. Earlier, a witness reported seeing two elderly men arguing in woods close to where Mr Wrighton's body was found.
On Friday, officers traced one of three "vital" potential witnesses - a man in his 50s who was seen changing into a T-shirt.
Police are still eager to speak to two other men. One aged 25 to 30, with tanned skin, was wearing a grey or blue t-shirt, grey gym shorts and heavy-duty flip flops. The other, aged 30 to 50, was wearing dark clothing and seen walking without a dog to the north of the heathland where Mr Wrighton had been walking.
Detectives also want to speak to anyone who may have spotted a black Ford Fiesta in the area.
A force spokeswoman told Sky News that despite the arrest police were "still appealing for anyone in the area at the time to contact them".
Mr Wrighton, a retired BT engineer from Banham, was married for 59 years and had two children. Paying tribute to him his wife Anne said he was a "lovely, gentle husband, dad and grandfather who was immensely kind".
Anyone with further information is asked to contact Norfolk Police on 0800 056 0944 or Crimestoppers on 0800 555 111.