Detectives have launched a renewed appeal for information about the murder of a grandmother who was bludgeoned to death while house-sitting.
Valerie Graves, 55, was found dead in Smugglers Lane, Bosham, on 30 December 2013.
She had been staying at the property while the owners were away over the Christmas period.
Forensic analysis of DNA from the scene has established the suspect is male but no match has been found.
Sussex Police said the DNA profile was "limited" and not suitable for a search on the National DNA Database.
In 2015 the force launched its biggest voluntary mass DNA screening in its history, asking all men aged over 17 who live, work or visit Bosham to provide a DNA sample to eliminate them from the inquiry.
To date 2,819 DNA samples have been taken.
Claw hammer attack
Ms Graves, a mother of two, was last seen alive at about 22:00 GMT on 29 December.
There were no signs of a struggle but a post-mortem examination found she had sustained severe head injuries after being hit with a claw hammer, probably around midnight.
Officers found the weapon 600 metres from the house in Hoe Lane.
Ch Supt Jason Taylor said: "Officers and staff from the investigation team remain determined to find Valerie's killer five years on and to get justice for her and her family.
"We continue to do everything reasonably possible to achieve this.
"We are still offering a £10,000 reward for information leading to the arrest and conviction of Valerie's killer and I would ask anyone who has information to contact police."
Last year Ms Graves' family spoke to the BBC to urge people with information to come forward, and her ex-partner Roy Wood, father to her children Tim Wood and Jemima Harrison, said: "We are just waiting and hoping that one day we will know what happened."