THE mother of a teenager stabbed to death at his 18th birthday party said she hopes her son's killer will be haunted for the rest of his life.

Mary Best's son Paul bled to death after David Mitchell, 19, plunged a kitchen knife into his back on February 13 last year.

Paul had been celebrating his birthday at home in North Crescent, Easington, County Durham, when Mitchell turned up and stabbed him with the five inch blade. He bled to death on his living room floor.

Mitchell was yesterday found guilty of manslaughter on the grounds of diminished responsibility after jurors at Newcastle Crown Court accepted his mild retardation reduced his responsibility for the killing.

Speaking after the verdict, Paul's mother Mary, 44, said: "I hope he sees our Paul every night in his cell with him. I want our Paul to haunt him for the rest of his life."

Mary said it is only the fact she has three other children, Jaymee, eight, Jack, six and Stephen, 20, that keeps her going.

"I will never get over Paul's death and couldn't even sit through the trial. I came for the verdict but couldn't go inside the court because the whole thing has made me ill."

Mitchell was initially tried last year but the jury failed to reach a verdict and his re-trial started last week.

Jurors cleared him of murder after hearing the evidence of seven psychiatrists who assessed his mental state.

Paul's aunt Sandra McDonald, 42, said the whole family have been devasted by the loss of Paul, who worked with his father Don, 61, at his building firm.

Mrs McDonald said: "It should be a life for a life and it is as simple as that. We wanted a murder conviction because then it would feel like he is being punished."

Mitchell, also of North Crescent, will be sentenced later this month after the preparation of a pre-sentence report.

Mary added: "The pain will never ease. I go to Paul's grave every day because it is the only way I can get some comfort.

"His killer wasn't even invited to the house that night, he just showed up."