The families of two lovers who were shot dead 35 years ago have said they are “haunted” by the killings and have issued a desperate plea for information.
The murders of mother-of-three Lindy Benstead and bricklayer Peter Thurgood continue to mystify detectives.
Three decades later their families have said: “It is never too late to do the right thing.”
The bodies of Mrs Benstead and Mr Thurgood were found near their rental car, off a road in West Sussex, on April 22 1986.
The pair – who were known to be having an affair – had been killed by shotgun blasts at point-blank range, police said.
However, despite numerous investigations over three decades, the case remains unsolved.
Detectives’ inquiries even took them to America, where a witness gave information naming a possible suspect, but police said they do not have evidence to corroborate this allegation.
Mrs Benstead, 49, and Mr Thurgood, 47, lived in adjoining Whitehill and Bordon in Hampshire, close to the West Sussex border.
On the day of the murders, Mr Thurgood hired a silver Mazda and drove to the Old Thorns Golf Club in Liphook, where Mrs Benstead worked as a cleaner.
They then drove to an open area off the A3, north of Petersfield.
A few hours later, a driver who had stopped for a rest found Mr Thurgood slumped by the side of the car with gunshot wounds to his head and chest, and Mrs Benstead was on the ground nearby.
In a joint statement, Mr Thurgood’s sons, David and Terry Thurgood, and Mrs Benstead’s daughter, Karen, said: “These terrible killings of our loved ones have haunted both families for 35 years now, and we remain united in our desire to support any inquiries that will help bring justice and closure for us all.
“We ask anyone who has any information they have not yet brought to the police to come forward now. It is never too late to do the right thing.”
David and Terry Thurgood said: “When we were growing up in the Bordon and Whitehill area in the 1980s everyone knew everyone as they were only small villages, and somebody must know something.
“Now is the time to come forward to the police and help both our families put closure to this horrific crime.”
Detective Superintendent Emma Heater, of the Surrey and Sussex Major Crime Team, said: “This tragic case was thoroughly investigated in 1986 and subsequently, and has since been reviewed several times.
“Many of our lines of inquiry over the years lead us to believe that the answer to the mystery of these dreadful crimes lies somewhere in the Whitehill and Bordon areas, from which the victims came.
“While we cannot rule out the possibility of an attack by a random stranger, it is still likely that someone with information from within those areas will provide vital leads.
“It is now 35 years since these tragic deaths and it may be that feelings and loyalties have shifted over the years, perhaps to a point at which someone is ready to disclose to us something they have never disclosed before.”
At the time of the murders and since, numerous people have been named as allegedly being involved, police said, and two arrests were made.
Ms Heater added: “All these leads were thoroughly explored but have not led to any further developments or arrests.
“There remain ongoing forensic inquiries, and further items are currently undergoing examination using techniques developed since 1986.”
Anyone who has any new information that might lead to new lines of inquiry can contact Sussex Police online or by calling 101, quoting Operation Bardwell.