A man has been arrested over the fatal stabbing of an 83-year-old dog walker in Norfolk woods, police said.
More than 100 police officers and staff are now involved in trying to track down the killer who brutally stabbed Peter Wrighton in Norfolk woodland.
He had been repeatedly stabbed in his neck and head, post-mortem examination tests showed.
A spokesman for Norfolk Police said the arrested man is now being held in police custody.
Elizabeth Truss said: "I am deeply shocked and saddened by reports of the death of local man in woodland near East Harling".
He was found by another dog walker with his two small dogs unharmed nearby about 10.45am near East Harling, Norfolk.
Mr Wrighton's wife of 59 years, Ann, said: 'Peter was immensely kind and never had a bad word to say about anybody and people always seemed to take a liking to him. He then drove his red Skoda 4.5 miles to The Street, close to the area where he walked his dogs.
Canon Steve Wright lighting a candle at Banham Church for murder victim Peter Wrighton
'We are extremely thankful for all the people who have come forward to speak with the police and hope we will soon be able to understand why this has happened. This was a particularly brutal murder and to do this, we need to piece together Peter's final movements to understand what happened to him and why.
CCTV of Peter at Keninnghall Post Office at 10.08am to 10.12am on Saturday 5th.
They also said they needed the "agreement of the coroner's officer" to release the identity of the victim.
One is aged 25 to 30, with tanned skin, was was wearing a grey or blue t-shirt, grey gym shorts and heavy-duty flip flops.
Police are following several lines of inquiry, including the theory the pensioner was killed by someone known to him, possibly even a fellow dog walker.
Anyone with information should phone the dedicated numbers set up to deal with calls about the incident, which are 0800 056 0944 or 0207 158 0010, quoting Operation Graduate.style="text-align: center;"