A "vulnerable" man who served 14 years in jail for murder was cleared and freed yesterday when the Court of Appeal accepted that his confessions to the police could not be relied on.

Ashley King, 34, was convicted in July 1986 of killing Margaret Greenwood, 58, who was bludgeoned to death at her home in Houghton-le-Spring, Tyne and Wear.

Three appeal judges quashed the conviction as "unsafe" after hearing fresh evidence from Olive Tunstall, a psychologist, that King had a low IQ bordering on mental incapacity and displayed signs of being "excessively compliant and suggestible". Ms Tunstall's branch of psychology was an "embryonic science" at the time of the trial.

A man of limited intelligence who spent 13 years in jail for bludgeoning a handicapped widow to death was freed yesterday when his conviction was quashed by the court of appeal after a seven-year fight.

Ashley King, then 22, was found guilty at Newcastle crown court in 1986 of the murder of Margaret Greenwood, 58, with a friend, Billy Waugh, aged 11 at the time.

Mrs Greenwood, 58, a polio victim who walked with calipers, was stabbed in the neck and battered to death at her home in Houghton-le-Spring, Tyne and Wear, in what was known as the "penny for the guy" murder.

The pair were said to have tricked their way into her house on Guy Fawkes night in 1985 by pretending to be collecting for bonfire night.

Under police questioning, King confessed to clubbing Mrs Greenwood over the head and claimed that Waugh had stabbed her. The conviction was quashed yesterday because of "new psychological evidence of King's vulnerability during police questioning," according to the campaigning group Justice.

Marilyn Kidd, Justice legal officer, said: "Justice is delighted by the court's judgment. It is a great day for Ashley. This is a sad case of a very vulnerable individual caught up in a system ill-equipped to deal with him. The result was that Ashley spent 13 years in prison for a crime he did not commit before his protestations of innocence were finally vindicated."

Billy Waugh, one of the youngest ever to be convicted of murder, was freed in 1987 at the age of 13 after the appeal court ruled that his conviction was "unsafe and unsatisfactory."

A man who served 14 years in prison for murder walked free from the Court of Appeal yesterday after judges accepted that his confessions could not be relied upon.

Ashley King's murder conviction was quashed in the light of new evidence showing that he had a low IQ and bordered on mental incapacity. Mr King, 34, is expected to receive compensation of at least £210,000.

The court was told that he was a vulnerable young man who showed signs of being "excessively compliant and suggestible".

The Lord Chief Justice, Lord Bingham of Cornhill, said that if the trial jury had heard this evidence it would have been "very hesitant" to convict Mr King, from Houghton-le-Spring, Tyne and Wear.

Mr King was convicted in July 1986 of killing Margaret Greenwood, 58, at her bungalow in Houghton-le-Spring.