A dentist who poisoned his wife and ex-lover's husband and then covered it up as a double suicide has been jailed for a minimum of 21 years.
Colin Howell, 51, from Glebe Road, Castlerock, Co Derry, was told by Mr Justice Anthony Hart at Belfast Crown Court that he will not be a free man again until 2031.
Last month he was sentenced to life imprisonment after pleading guilty to the murders of his wife Lesley, 31, the mother of their four children, and policeman Trevor Buchanan, 32.
Mr Buchanan was the husband of the woman with whom Howell had been having an affair at the time in May 1991.
Hazel Stewart, 47, a mother of two from Ballystrone Road, Coleraine, Co Derry, who later remarried, is due to stand trial next February for the two murders. She denies the two charges.
Judge Anthony Hart said: 'These were truly heinous crimes, constituting as they did the coldblooded, carefully planned and ruthlessly executed double murder of two people who Howell saw as standing in the way of his adulterous desire to be with Hazel Buchanan.'
He said each murder was carried out while the victims were asleep and defenceless.
'Even when each stirred in their sleep, Howell did not draw back and spare their lives, but physically subdued their faint signs of approaching consciousness, thereby ensuring their deaths,' he added.
Howell, dressed in a grey suit, gave no reaction as the sentence was handed down.
In 1991, the bodies of Colin Howell’s wife Lesley, aged 31, and RUC constable Trevor Buchanan, who was 32, were found in a car filled with exhaust fumes. It was concluded at the time that the couple had died in a suicide pact.
Constable Buchanan's wife Hazel was having an affair with Colin Howell and the trial judge said the couple were murdered because Howell saw them standing in the way of his adulterous desire to be with her.
Since re-married, Hazel Stewart is also accused of the two murders and is to stand trial next February.
