Nigel Acres, the partner of Valerie Graves' sister, said: "We would ask anyone who is eligible to attend one of the screening sessions and give their DNA. "This is a difficult case and we know the police are doing all they can to solve it. "The DNA screening is an important part of the investigation. Please help."
The DNA screening sessions are taking place at the Millstream Hotel today and tomorrow, and from Monday 2nd February to Saturday 7th February and from Tuesday 10th February to Sunday 15th February. All sessions are from 10am to 8pm.
Artist Valerie Graves, 55, was found dead in a ground floor bedroom of a house she was looking after for friends on 30th December 201
Today's DNA screening is a last resort for Sussex Police who have interviewed more than 9,500 people as part of the extensive inquiry into the murder of Valerie Graves.
A BBC Crimewatch appeal and a £20,000 reward have failed to yield any suspects or charges.
On the first-year anniversary of the murder last month, officers handed out leaflets and put up posters about the DNA screening.
Graves' death shocked the small community of Bosham, which featured in an episode of the ITV crime drama Midsomer Murders.
Mass voluntary DNA screening is set to begin by police investigating the unsolved murder of a grandmother in the West Sussex village of Bosham.
Men who live, work or visit the area are being invited to eliminate themselves from suspicion by providing a mouth swab and thumbprint.
Artist Valerie Graves, 55, was found dead in a ground floor bedroom of a house she was looking after for friends on 30th December 2013.
The DNA screening will take place at the Millstream Hotel in the village from today, with posters alerting locals about the dates the screening will take place.
A 55-year-old woman who was murdered while house-sitting in a quiet seaside village in West Sussex died from "significant head and facial injuries", a post-mortem has revealed.
Valerie Graves was found dead in the property in Smuggler's Lane on Monday morning. She had been house-sitting with three other members of her family over Christmas while the owners of the home were on holiday.
Sussex Police are continuing to appeal for witnesses to come forward, and investigations are continuing. Detective Chief Inspector Jon Fanner said:
"The post-mortem has revealed the cause of death but we are still keeping an open mind as to the motive. We are appealing for witnesses who may have seen anyone acting suspiciously or anything unusual in the area from late afternoon on Sunday 29 December to around 10am on Monday 30 December.
"Please call us if you know anything, no matter how insignificant you might think it is. It could be important to the investigation."
Earlier this year, the CPS admitted this was a missed chance to charge Savile while he was alive, because victims were not taken seriously enough.
Alison Levitt QC found that "had the police and prosecutors taken a different approach" prosecutions could have been possible in relation to three victims.
Two Sussex Police detectives who dealt with a sex crime claim against Jimmy Savile in 2008 have been referred to the IPCC police watchdog.
A woman came forward in March 2008 to claim that disgraced television presenter Savile assaulted her in a caravan in around 1970 when she was in her early 20s.
This was referred to prosecutors with three other allegations against the performer received by Surrey Police, but in 2009 the Crown Prosecution Service decided no action could be taken.
A police officer from the force overseeing major anti-fracking protests has received "management advice" after labelling activists as "scum" on Twitter.
The comment was picked up by a member of the public, who tweeted, "#balcombe @sussex_police should your officers really be calling protesters 'scum' on twitter? I suggest you issue some guidance ASAP."
The force said in a statement: "Sussex Police has received a report of a personal Twitter account belonging to a Sussex officer, which is abusive to protesters at Balcombe.
"We have worked hard to engage with everyone involved in and affected by the activities surrounding the drilling operation at Balcombe and no matter who authors them, such comments are unhelpful and not acceptable."
Sussex Police have been explaining some of their methods to move protesters at the anti-fracking demonstration in Balcombe, including the use of pressure points.
A former police community support officer (PCSO) is to appear in court charged with stealing £9,000 from passengers at Gatwick Airport in April.
Alexis Scott, 39, of High Grove in London, is charged with multiple counts of theft and misconduct in a public office.
She was dismissed from Sussex Police for gross misconduct after an initial investigation and will appear at Canterbury Magistrates' Court on 2 September.
Police say they have arrested about 30 protesters in Balcombe today and have taken them to a number of different police stations across Sussex.
There were no further details of charges.
Sussex Police Superintendent Lawrence Hobbs told ITV News that he had no choice but to arrest those who would not go peacefully.