A MAN, who would have got away with the ''perfect crime'' if he had kept his mouth shut, was jailed for life yesterday for murdering the mother of his child by smothering her with chloroform.

Temporary judge Roderick Macdonald QC ordered that Craig McCreight should serve at least 18 years for ''an act of unspeakable evil''.

McCreight, 30, had pled not guilty to murdering Yvonne Davidson on February 7 or 8, 1999, at the home they shared in Fairnsfell, Broxburn, West Lothian, by placing chloroform at her mouth and nose as she lay asleep in bed and causing her to inhale it.

He denied rendering the 34-year-old mother of three unconscious, taking her downstairs, dressing her, and dumping her outside - either dead or dying - in a neighbour's garden in sub-zero temperatures. But after a four-week trial at the High Court in Edinburgh, a jury took just over three hours to convict him of murder by a majority verdict.

Mr Macdonald told McCreight that he had ''devised a scheme to rid yourself of the woman with whom you lived by ending her life. You spoke of getting rid of her and acquired chloroform to achieve your purpose.

''Since then, you have displayed no remorse, only what I regard as utter hypocrisy in the way you behaved at the time of her death and thereafter, even to the extent of exhibiting her photograph . . . in the living room.

''The crime you committed was an act of unspeakable evil. It was almost the perfect murder.''

Had it not been for the fact that a friend, David Stewart, could not live with the knowledge of what McCreight had done, he might not have been brought to justice.

McCreight and Ms Davidson had been living together since 1994 and daughter Abbi was born in 1997. She also had two children from a previous relationship.

Ms Davidson ran the Clifton Arms in Broxburn, a ''Rangers pub'', and friends said she was a happy-go-lucky person who lived for her children and her pub.

But the relationship ran into serious trouble after she discovered McCreight's previous girlfriend was expecting his child.

McCreight confided in Mr Stewart: ''She is doing my head in . . . I need to get rid of her.'' There had been mention of giving her insulin, but Mr Stewart told McCreight not to be so silly.

A couple of months before Ms Davidson's death, McCreight showed Mr Stewart a medicine bottle he was carrying in his jacket and asked Mr Stewart to smell it. Mr Stewart was immediately hit by a wave of nausea.

''He said his friend had got it for him and it was chloroform. He said that would do it and they would not be able to trace it. To me it meant he was serious about what he had been talking about . . . to bump Yvonne off.''

McCreight was questioned after his partner's body was discovered, but there was no reason at the time to suspect foul play and the cause of Ms Davidson's death was put down to hypothermia and her use of amphetamine.

McCreight arrived at Mr Stewart's home the following day. ''He said: 'What a buzz.' I took it that it had been him that done it.''

Mr Stewart did nothing about the claims then and McCreight even went on to be best man at his wedding, but Mr Stewart said: ''I could not live with it.''

His information led to a further check on a blood sample of Ms Davidson's, which confirmed the presence of chloroform and cause of death as chloroform poisoning.

His story was backed up by Gary Espie, 37, another friend McCreight talked to two days after the victim was found.

''He said . . . it was him that had killed Yvonne,'' Mr Espie said. McCreight held the rag over her face ''until she stopped wriggling''. But he thought McCreight was telling a tale to be a ''big man'' and did not say anything to police until December 2000.