Killer dentist Colin Howell has told a court that his former lover Hazel Stewart did not object to his plan to kill her husband and his wife so they could be together.
Taking the stand to give evidence against Stewart, Howell said that he needed her help to make sure that his plan to murder their partners would work.
The 51-year-old said he came up with the plot as he lay in bed with his wife on May 13, 1991, just days before the murders.
Stewart (47) denies murdering her husband Trevor Buchanan and Howell’s wife Lesley in May 1991. Their bodies were discovered in a fume-filled car in Castlerock in an apparent suicide pact.
Howell has already pleaded guilty to the murders and was jailed for 21 years.
The killer told Coleraine Crown Court that the day after he decided to murder the pair he asked Stewart to meet him so he could share his “solution” with her.
“Her first reaction was ‘we’ll be caught’. She was afraid of being caught. She said if she was caught she would slit her wrists.
“There had never been any talk before about killing Lesley and Trevor. I suspect she believed I had a plan to run away together. I wouldn’t have left Lesley because of the children,” he said.
Howell added however that Stewart “didn’t object to the |principal of killing Trevor and Lesley”.
He said he told Stewart that he needed her to give her husband tablets to fall asleep before the murder.
“She took the tablets and put them in her handbag. When I gave her the tablets she understood the full plan. I felt it was the moment when the plan was agreed upon,” he said.
The court was told that on the night of the murder Howell saw a tuna sandwich on a counter in the Buchanans’ kitchen with bits of blue tablet visible.
“I was annoyed that my accomplice hadn’t been careful to crunch them up finely enough. It was clumsy.”
On the night of the murder, which was the same day as his son’s birthday party, his wife was asleep in their living room. Howell said he hooked a hose pipe to his car, stretched it into the living room, placed the nozzle by his wife’s mouth and then turned on his car engine.
Once he was sure his wife was dead he opened the windows and then called Stewart to say he had “finished” with his wife.
He then placed her body in the boot of the car, freewheeled the car out of the driveway, then drove past Coleraine police station to the Buchanans’ home.
He said Stewart opened the garage for him and he stretched the hose into Mr Buchanan's bedroom where he was sleeping. Mr Buchanan stirred and during a struggle Howell forced the nozzle into Mr Buchanan’s mouth and he went limp after a few breaths. He then drove both bodies to his late father’s house in Castlerock where he staged a suicide scene.
Howell said his relationship with Stewart resumed about five or six weeks later and continued until 1996.
“We were trying to make something work which had begun with adultery then murder. We were trying to make something work that was rotten to the core,” he told the court.
Howell said he proposed to Stewart in 1995 and asked her to start a new life with him and their children in Scotland, but she turned him down.
“It changed after that. It became dark and difficult and challenging. I was relieved when she said no. It was a co-dependency linked by a dark secret. I proposed almost out of duty. I had killed her husband and left her two children fatherless. I didn’t feel I could end the relationship.”
He said the relationship continued on and off for another year but that he then discovered that Stewart was having an affair with someone else.
“It took about a year before I realised I was being two-timed. I was thinking to myself ‘I have been such a fool’. I was angry with myself. I felt so humiliated.”
Howell said that Stewart called him “in her soft, silky voice” to apologise and asked him to call to her house so that they could talk.
“I have been accused of not being able to let go. But as far as I was concerned the relationship ended quite a few months before it had for Hazel,” he said.