Police said Valerie, a 55-year-old mother and grandmother, was found brutally murdered in her bedroom in Smugglers Lane on December 30 2013 — but the killer is yet to be found.
She had been staying at the property while the owners were away over the Christmas period, according to police.
"A detailed investigation, including an exhaustive forensic search of the crime scene, allowed forensic scientists to obtain a limited DNA profile, which although not suitable for a search on the National DNA Database indicated the suspect is male," a police spokesman said.
"In 2015 Sussex Police 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."
According to police, this meant that, to date, detectives from the Surrey and Sussex Major Crime Team have taken 2,819 DNA samples from men from Bosham or associated to the enquiry in some other way.
Chief superintendent Jason Taylor said the investigation team 'remain determined' to find Valerie's killer five years on and to 'get justice for her and her family'.
He added: "We continue to do everything reasonably possible to achieve this.
"We are still offering a Â£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."
Police said Valerie's family urged anyone with any information about her death to come forward and contact police or crimestoppers.
Police asked anyone with information about the murder of Valerie Graves to report it online or ring 101 quoting Operation Ensign.
Alternatively you can contact independent charity Crimestoppers anonymously on 0800 555 111 or through the non-traceable anonymous online form.
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