The fiancee of a 42-year-old man who was murdered in the back garden of his Liverpool home has made an appeal for information a month after his death.
Colin Hughes was stabbed to death in Old Swan on 21 September as he went to investigate a noise at the back door.
Four people have been arrested in connection with the killing and are on police bail. No one has been charged.
Paula Greenwood said: "Somebody knows something about it. You can't keep something like that to yourself."
Ms Greenwood, 46, said the couple had been playing cards at their Baden Road home, when they heard the glass of the back door smash at about 0045 BST.
She went to call the police and shouted for her children while Mr Hughes, a chef at a local pub, went to see what had happened.
Her 18-year-old son Kyle followed Mr Hughes into the garden.
"When he came back he said he [Mr Hughes] had been stabbed," Ms Greenwood said.
"He was lying face down on the floor. From what I could see - because it was very dark - blood was coming from the side of his body.
"I was saying: 'Wake up, wake up'."
He was taken to hospital but died soon afterwards. A post-mortem examination found he died from a single stab wound.
Ms Greenwood said the family had been left "shocked and devastated".
"He was such a loving man. Why would anyone want to do this?"
"You don't go round stabbing people and carry on with ordinary life. We can't."
Det Supt Laurence Carr is leading the investigation for Merseyside Police.
He said: "I am keeping an open mind about the motive but I have discovered nothing to date that would indicate why this sort of attack would take place against Colin Hughes."
He said a witness had seen a man who could have been one of the killers. He was described as 5ft 10 (1.78m), of slim build, with a black tracksuit and hood up.
He is also keen to trace Mr Hughes' movements between 2000 and 2030 BST on the night he died.
Anyone with any information should contact Merseyside Police.