A man arrested on suspicion of murdering a woman, whose body was found in National Trust woodland, knew the victim, police have said.
Officers found the body of the woman, in her 60s, on the Watlington Hill estate, Oxfordshire, just before 18:00 BST on Friday.
The 23-year-old arrested man was found seriously injured and remains in hospital in a stable condition.
Thames Valley Police said it did not believe it was a random attack.
The force said it was linking the murder to reports of a man seen acting suspiciously near the Fox and Hounds pub on Christmas Common, near the park, a few hours earlier at about 15:30, and have appealed for anyone who saw the man to get in touch.
One neighbour, who did not want to be named, said: "We heard a helicopter going over and there were a lot of police cars, we didn't actually know what was going on."
They added: "It was very unsettling as it could have been our house that he had gone into.
"It's a quiet village so it's a bit disconcerting."
Det Supt Craig Kirby said: "We believe that this was not a random attack and that the victim and the attacker were known to each other.
"The arrested man remains in the custody of police officers while he receives hospital treatment for serious injuries."
The woman's next of kin have been informed and are being supported by specially trained officers.
Formal identification processes and a post-mortem are yet to be carried out.
Officers are appealing for any information in relation to the death.