Dentist Howell's wife called out to children as he poisoned her on sofa
Dentist Colin Howell murdered his wife and his lover's policeman husband by poisoning them with car exhaust fumes as they slept, a court heard yesterday.
Howell then fooled investigating police by stage-managing a scene to make it look as if they had died in a suicide pact, Belfast Crown Court heard.
He kept the secret for almost 20 years before confessing to detectives.
Howell, 51, first killed his wife Lesley and later Constable Trevor Buchanan at their homes in Coleraine, Co Londonderry, in May 1991 when he attached part of a baby's feeding bottle to a garden hose to poison them with carbon monoxide fumes from a car.
Details of the double murder were revealed for the first time at a pre-sentence hearing for Howell, who has pleaded guilty to the murders.
Crown lawyer Kieran Murphy told Mr Justice Anthony Hart: "This was a meticulous and devious plan, and pre-meditated in a manner that might be described as professional."
Howell, of Glebe Road, Castlerock, Co Londonderry, has already been sentenced to life imprisonment and will be told on Friday the minimum term he will serve.
His former lover, mother-of-two Hazel Stewart, who remarried after Constable Buchanan's death, has pleaded not guilty and her trial, which is due to begin in early February, is expected to last up to a month.
The court also heard today that two years after he remarried, Howell told his second wife Kyle about the killings but his admission was not disclosed until January last year, when he confessed all to his church elders.
Howell and Constable Buchanan's wife had resumed their affair when the dentist decided to carry out the murders late on May 18 and the early hours of May 19.
The first was in his own house where his wife, who had been drinking and taking prescription tablets because of her distress over the affair, was sleeping in her nightdress on a sofa.
Howell attached the hose to the exhaust of her Renault Savanna by using the bottle, which he cut in half. He ran it to where his wife was lying, switched on the engine and waited at the living room door.
But she woke up and cried out for her son Matthew, then aged six, who was sleeping in another room with his sister Lauren, four, and two brothers, Daniel, two, and Johnny, nine months.
Howell then pulled a duvet over her head, pushed the hose into her face with his right hand and held it there until she died.
Mr Murphy said: "She called out Matthew, his son's name, and he said that memory haunts him."
The court heard that he then dressed his wife and put her in the boot of his car.
He drove the Renault from his home at Knocklayde Park to where Constable Buchanan lived with Hazel and their two young children, Andrew and Lisa, at Charnwood Park, Coleraine.
The police officer was asleep in the double bed. Howell drove into the garage and did the same thing with the garden hose. But his second victim also woke up to find Howell, the court heard.
They struggled and fell to the floor. Howell managed to trap the officer's arms inside a quilt and pulled it over his head. He shoved the hose towards his face and listened as the policeman took his final breaths.
Constable Buchanan, a scenes-of-crime officer with the Royal Ulster Constabulary, was also dressed. His body was carried outside and placed in the boot beside Ms Howell's.
He headed to a row of houses at Cliff Terrace. One of them, number six, had been owned by his wife's father, Harry Clarke, who had collapsed and died at his daughter's home 12 days earlier.
It was here, in a small garage, that Howell stage-managed the suicides.
He heaved the man's body from the boot and placed it in the driver's seat and left the door open. Howell's wife, who had three abortions before she married him in 1983, was in the boot.
He positioned some family photographs beside her body.
Howell then connected a length of vacuum hose to the exhaust and put the other end into the boot. Before leaving he switched on the ignition.
The court then heard of an elaborate plan by Howell to cover up the murders.
The following morning he called police to see if his wife had been in an accident as she had been drinking.
He then alerted one of his church elders, Jim Flanagan, and asked him to go to Cliff Terrace to see if his wife was there.
He didn't find them at first, but when he went back a second time, the bodies were found in the car.
Mr Murphy then read extracts from an extensive series of interviews Howell gave to police after his arrest.
They disclosed how he had given the impression that his wife and Mr Buchanan had committed suicide because they had struggled to cope after discovering he and Ms Stewart had been having an affair.
At the time, Howell claimed Mr Buchanan had come to his own house and the pair had an altercation, which resulted in the policeman striking him before leaving.
Howell said he awoke the next morning to find his wife gone, leaving a note in the house.
He then rang a member of his church and the authorities to report her missing.
Mr Murphy said: "That statement was a planned cover-up of the murders to escape detection and stop the investigation."
The court heard he wanted to start a new life with his lover and for that he needed his wife and Ms Stewart's husband dead.
While Howell claimed money had not been the motive for the killings, the court heard he benefited financially from the deaths of his wife and father to the tune of more than £400,000.
Mr Murphy said Howell was able to pay off debts and develop his dental practice in Ballymoney, Co Antrim.
But then the court heard Howell lost £353,000 on a Philippines scam involving a scheme to recover gold..
Mr Murphy urged the judge to impose a severe sentence.
He added: "The actions of the dentist were calculated, callous, manipulative, evil and wholly without mercy for two defenceless victims, one of whom was his wife and the other the loving husband of his co-accused."
Howell's lawyer, Richard Weir QC, told the court the delay in the guilty plea was caused by advisors probing Howell's mental state.
"Anyone knowing Colin Howell before and indeed after these deeds would find it unimaginable that he could do these monstrous things because he was an upstanding, an effective and a worthy member of this society, not a monster," he said.