A man has been arrested over the “brutal” stabbing of an 83-year-old dog walker.
The body of Peter Wrighton was found three miles south of East Harling in Norfolk on 5 August.
Norfolk Police has arrested a local man, in his 20s, on suspicion of murder and he remains in custody while inquiries continue.
Meanwhile, roadside police patrols have been held in the area to jog people’s memories a week after the fatal attack.
Mr Wrighton, from Banham, had been repeatedly stabbed in his neck and head, post-mortem examination tests showed.
The grandfather’s body was found near to Fiveways Junction by a member of the public at about 10:45 BST. His dogs, Dylan and Gemma, were found close by.
On Saturday, officers stopped cars to speak to people who may have been passing the murder scene around the time of the attack.
There were also horse patrols in the village to reassure residents.
A force spokeswoman said despite the arrest police were “still appealing for anyone in the area at the time to contact them”.
In particular, detectives want anyone who may have spotted a black Ford Fiesta to get in touch.
On Friday, police said they had traced one of three “vital” potential witnesses – a man in his 50s seen changing into a T-shirt – but they said they still wanted to speak to two other men.
One is 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.
Det Supt Andy Smith, who is overseeing the inquiry, said on Friday that more than 220 people had been in touch.
Search teams have used metal detectors and dogs, with more than 100 people working on the investigation.
Mr Wrighton, who was married for 59 years and had two children, was described by his family in a tribute as “immensely kind”.