An 83-year-old man was stabbed to death while out walking his two dogs in Norfolk woodland, say police.
The body of the man was found on Saturday near the Fiveways Junction in East Harling.
A post-mortem examination has found the man died of multiple stab wounds to his neck and head.
Ch Supt Mike Fawcett, of Norfolk Police, said he could understand the shock of the community at the “level of brutality”.
The man was described as a “family man from the local area”.
He added: “The motive remains unclear and we are appealing for people who have noticed any unusual activity in the area recently.
“Those who use the woodlands and footpath regularly, especially whose who were there between 9am and 11am on Saturday 5 August, are urged to contact us. ”
That he said “dedicated teams” were investigating the case and a mobile police station has been set up at the scene.
A cordon remains in place.