Detectives have pledged to continue doing everything they can to catch the killers of a Leeds businessman who died during a robbery at his home 12 years ago.
John Luper was 57 years old when he died at his home in Sandmoor Drive, Alwoodley, on February 17, 2004.
He had been attacked by a group of four or five masked men as he walked his dog near his neighbour’s driveway at about 11.30pm on February 16 before being dragged back to his home.
His wife, daughter and the family’s au pair were tied up and left in an upstairs bedroom before the suspects left the property.
When they managed to free themselves, they found Mr Luper unconscious on the kitchen floor.
Police were called at 1.45am and despite attempts to resuscitate him he was pronounced dead at the scene. A post mortem examination showed he died as a result of asphyxiation.
Jewellery and cash totalling around £100,000 were taken during the robbery. Among the pieces of jewellery was a rare Cartier watch that was platinum with vertical rows of diamonds either side of the face.
Officers are still keen to hear from anyone who may have been offered such a watch for sale.
Detective Superintendent Simon Atkinson, of West Yorkshire Police Homicide and Major Enquiry Team, said: "We remain absolutely determined to get justice for John Luper and his family and are actively continuing to investigate his murder.
"Although 12 years have now passed, our resolve remains as strong as it was on the first day of the investigation.
"We are still convinced that there will be people out there, most likely in the criminal fraternity, who know who was involved in Mr Luper’s murder.
"Allegiances can often change over time and it could be that someone is in a better position now to pass on what they know, either direct to us or anonymously via Crimestoppers.
"John Luper was taken from his family in such a sudden and traumatic way, and I know the passage of time has not diminished the pain and loss they feel.
"I would urge anyone who can provide any information that could assist in bringing those responsible to justice to contact us."
Anyone with information is asked to contact West Yorkshire Police's Homicide and Major Enquiry Team via 101. Information can also be passed anonymously to the independent charity Crimestoppers on 0800 555 111.