The family of a grandmother bludgeoned to death in bed as she house-sat for friends five years ago fear her killer may never be caught.
Valerie Graves, 55, was found dead at a property in Smugglers Lane, Bosham, on 30 December 2013.
Forensic analysis of DNA from the scene established the suspect was male but no match has been found.
The artist's ex-partner Roy Wood, of Portslade, said of police: "I don't feel there's much more they can do."
His comments come after Sussex Police confirmed it had ended a huge DNA screening programme which saw almost 3,000 men tested.
He said the family had avoided talking about it when they met last week for a festive meal, adding: "It's difficult. People expect there will be answers immediately but not when it's something as random as this."
The mother-of-two was last seen alive at about 22:00 GMT on 29 December.
She had been staying at the property while the owners were away over the Christmas period.
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.
Officers found the weapon 600 metres from the house in Hoe Lane.
The force carried out the 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 but no match was found.
Renewing an appeal for information, Ch Supt Jason Taylor said the investigation team remained "determined" to find Ms Graves' killer to to get justice for her and her family.
"We continue to do everything reasonably possible to achieve this," he said.