The court in Douglas, Isle of Man, found Tony Teare, an apprentice engineer, guilty of killing a 22-year-old woman for a payment of pounds 600.
Judge Henry Callow told him: 'You have been found guilty of the cold and calculated killing of a defenceless young woman.
'I can pronounce only one sentence. You will be taken to the Isle of Man jail and thence to a place of legal execution and there hanged by the neck until you are dead.'
The Isle of Man is the last place in the British Isles to repeal capital punishment. When Britain did so in 1965, neither the Isle of Man nor the Channel Islands brought their legislation into line.
The Manx parliament, Tynwald, has also kept corporal punishment on its statutes but local magistrates have been given firm advice not to order birching after the European Court of Human Rights judged it to be 'cruel and unusual'.
Now, Miles Walker, the Chief Minister, has announced that capital punishment is to be abolished under a new Bill to be introduced in the autumn.
Murders are infrequent on the 227-square mile island, and the fact that its laws on capital punishment were going to cause a problem did not arise until 1972 when the head chef of a fast-food restaurant battered his manager to death with a fire extinguisher. When the murder charge was proved the law forced the judge to order the death penalty.
It created a legal precedent when the Queen exercised her Royal Prerogative and the sentence was commuted to life imprisonment.
In 1982 a father beat his baby son to death - the same procedure was followed and the death sentence overturned.
A similar course of action is sure to be followed after the death sentence handed out to Tony Teare yesterday.
Teare, of Ormly Road, Ramsey, had denied murdering Corinne Bentley at a remote Manx farm a year ago.
Michael Moyle, for the prosecution, told the court that Teare became a 'contract killer' for pounds 600 to pay off a bank overdraft.
He said Ms Bentley, who had a mental age of 15, had moved in with her boyfriend, Elliot Kinvig, who owned 111 acres (44.4 hectares) and a farmhouse. He lived there with his mother, sister and brother-in-law.
Mr Kinvig's family said they wanted her evicted but Mr Kinvig threatened to oust them instead. His brother-in-law is alleged to have told Teare, a work colleague, that he wanted the girl dead.
Mr Moyle said that on 11 July last year, Teare lured Ms Bentley to remote moorland, promising her a job interview. He then cut her throat with a Stanley knife, beat her and left her for dead. She staggered 350 yards to a farmhouse where she stumbled into a disused silage pit.
Her body was found 12 days later.
In a confession Teare said he had thought pounds 600 too little for the job but needed the money.
Robert Jelski, for the defence, said that the case relied only on the confession and unreliable evidence. Nothing was found on his client's clothing or in his home to link him to the killing, and he maintained the prosecution had failed to prove its case.
Mr Moyle told the jury the murder was heartless and 'one of the most wicked and horrific of crimes' committed on the island.
Last night Teare was being held in solitary confinement in Douglas to await the commuting of his death sentence, a process that could take two weeks. He will then be moved to mainland Britain to serve his life sentence.