Sharif Demirsay death: Police offer £10,000 reward
Police have offered a £10,000 reward for information leading to the killers of a grandfather who was stabbed to death at his Bedfordshire home.
Serafettin Demirsay, 65, died in an attack by three men who forced their way into his house in Vineyard Way, Kempston, on 14 May.
Four men, aged 17, 18, 19 and 24, have been arrested on suspicion of murder and bailed.
Officers hope the money will help to "tip the balance" of the investigation.
Turkish-born Mr Demirsay, known locally as Sharif, was stabbed to death after answering a knock at the door at about 21:30 BST.
His 68-year-old partner, who had lived with him for more than 20 years, tried to stop the attack before being hurt herself.
She was threatened and stabbed in the arm.
The offenders stole about £1,000 and jewellery of sentimental value.
Det Chief Insp Tim Redfearn said: "Sharif was a much loved family man who did not have any apparent enemies and in no way deserved to be attacked in his own home.
"Someone out there has vital information which we need to tip the balance in the investigation and the £10,000 reward is the incentive to get that person to come forward."
Police said they are also still searching for the murder weapons, believed to be kitchen knives, that could have been discarded in hedgerows or gardens by the killers as they left the scene.