One of three "vital" potential witnesses to the murder of an elderly dog walker in woodland has been traced, police have said.
The body of Peter Wrighton, 83, was found three miles south of East Harling in Norfolk on 5 August. He had been repeatedly stabbed.
Norfolk Police said they wanted to trace three men seen around the woodland close to the time he died.
The force said a man in his 50s seen changing into a t-shirt has been found.
Police say they still want to speak to two other men; one aged 25 to 30, with tanned skin, wearing a grey or blue t-shirt, grey gym shorts and heavy-duty flip flops; the other aged 30 to 50, wearing dark clothing and seen walking without a dog to the north of the heath.
Det Supt Andy Smith added: "We have already heard from more than 220 people but we will be exploring all avenues in our enquiries and we are still keen to hear from more.
"We also want to hear from delivery drivers who might have travelled through or have been in the area on Saturday and who could have important dash cam footage for us to review. In addition, anyone else with images or footages of the area should contact us."
There have been no arrests and no weapon has been found.
Mr Wrighton was pictured on CCTV using the post office in Kenninghall at 10:10 BST, about 35 minutes before his body was found near to Fiveways Junction.
"His car, a red Skoda Fabia, was parked close to The Street, the road close to the heath land where he was walking his dogs Dylan and Gemma," Det Supt Smith said.
The force said it has more than 100 officers and staff working on the "significant murder investigation".