A ruthless dentist who murdered his wife and ex-lover's policeman husband as they slept and then covered it up as a double suicide was jailed for a minimum of 21 years yesterday.
Colin Howell, 51, from Glebe Road, Castlerock, Co Londonderry, was told by Mr Justice Anthony Hart at Belfast Crown Court that he had committed truly heinous crimes and showed no mercy to two defenceless victims.
Last month he was sentenced to life imprisonment after pleading guilty to poisoning his wife Lesley, 31, the mother of their four children, and Pc Trevor Buchanan, 32, husband of the woman with whom he had been having an affair at the time in May 1991.
The dentist killed both in their respective homes in Coleraine on one night when he attached part of a baby's feeding bottle to a garden hose to poison them with carbon monoxide fumes from a car.
Mr Buchanan's wife Hazel, 47, a mother of two from Ballystrone Road, Coleraine, Co Derry, who later re-married taking the name Stewart, is due to stand trial next February for the two murders. She denies the two charges.
Howell's crimes only came to light two years ago when he confessed his dark secret to elders in his church and then police.
Including time already served in prison, he will not be considered for release until 2029.
Mr Justice Hart said: "These were truly heinous crimes, constituting as they did the cold-blooded, 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 victim was asleep and defenceless - Mrs Howell on the sofa and Mr Buchanan in his bed.
Both woke as the fumes started to overcome them, but Howell overpowered each of them before allowing the deadly gas to finally kill them.
"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," the judge added.
Howell, dressed in a grey suit, white shirt and striped tie, gave no reaction as the sentence was handed down. Earlier he bowed his head and closed his eyes as the judge described how he had killed each of his victims.
Members of both Mrs Howell and Mr Buchanan's families sat in silence in the packed public gallery throughout the half-hour sentencing hearing.
Mr Justice Hart said there were many aggravating factors which required a heavy sentence, among them the fact that it was a double murder and that Howell benefited to the tune of £414,000 from his wife's death.
Two innocent people were murdered and six children deprived of the love of their mother and father, he added.
The judge said this pain was intensified because the families had to live with the false belief that their loved ones had died in a suicide pact - an extra burden Howell let them bear for almost 20 years.
"He is an intelligent man who knew exactly what he was doing throughout," the judge continued.
He said that, had Howell not confessed to his guilt, he could have sentenced him to a minimum of 28 years.
As it is, he will be around 70 when he is considered for release.
Mr Justice Hart added: "Not only were their children deprived of the love and companionship of their respective parents throughout their childhood, but their brothers and sisters also suffered grievous loss."
The judge had been provided with victim impact statements from both bereaved families.
"It is particularly poignant to read the descriptions of the effect of the death of their son on Trevor Buchanan's elderly parents, whose remaining years were blighted by the severe effect of their son's death upon them," he told the court.
"The premeditated and ruthless way the murders were planned and carried out, the grave effect they had on the lives of so many others, the financial benefits to Howell and the pain and grief he allowed others to experience for so many years before he confessed his guilt are all aggravating factors that must be reflected in the minimum term he must serve before he can be considered for release."