The son of double murderer Colin Howell has said he aspires to forgive his father one day after he killed his mother and his lover’s husband – despite only confessing to the murders 18 years later
The son of convicted double murderer Colin Howell said his life “fell apart” when he found out his father killed his mother Lesley, as well as his secret lover’s husband Trevor Buchanan.
Howell was having an affair with a woman named Hazel Stewart, and in a sick and twisted fate, killed his wife Lesley, as well as Stewarts husband Trevor. Howell attempted to make the murders look like a suicide pact, which police originally thought when they found the two bodies in a fume-filled garage in Castlerock in 1991.
Police thought the pair had taken their lives after discovering their partners were having an extra-marital affair, but the sinister truth was revealed 18 years later, in January 2009, when dentist Colin Howell walked into a police station in County Londonderry, and admitted to the murders of his wife Lesley, and Trevor – who was the husband of Howell’s former lover Hazel Stewart.
READ MORE: Double killer denied child porn was his despite chilling murder confessions
It was revealed the victims had been drugged and murdered with their bodies arranged to appear as if they had committed suicide. In November 2010, Howell pleaded guilty to murdering his wife and Buchanan and was sentenced to life imprisonment, with a minimum term of 21 years before he could be considered for release.
Just over a year later, Howell also pleaded guilty to sexually assaulting a number of female patients while working as a dentist at his Ballymoney practice. He was sentenced to five-and-a-half years for these indecent assaults, to be served concurrently with his life sentence, and was also stripped of his NHS pension as a result.
He also denied sick child porn found on his computer were his. The images were discovered on January 30, 2009, more than 17 years he murdered the pair. Howell, now 67, was then quizzed about a series of pictures of children aged around seven years old that had been found by the investigating officers.
Given his minimum term of 21 years, Howell is still serving his sentence as of January 2026 at HMP Maghaberry in Northern Ireland and is not eligible for parole until at least 2031. Stewart was sentenced to life imprisonment with a minimum of 18 years and was sent to Hydebank Wood in Belfast.
In 2025, Stewart failed in a legal bid to secure a reduction in her jail sentence for her part in the murders, claiming she had been under Howell’s “coercive control” at the time and that new medical evidence should be considered.
Now the children of Colin and Lesley have spoken out about the harrowing account of what happened in 1991. Taking part in the new ITV documentary Killer in the House, Seamus Daniel, who is now a doctor in New York, along with his siblings Lauren and Jonathan told their side of the story.
Seamus said he doesn’t “buy into” Stewart’s claims of coercive control and urged her to just “say sorry” instead. The doctor said when he first heard of the news: “There were a number of reactions, the first was disbelief and the next was disgust. Definitely layered in there was a lot of anger because this person had been so controlling.
“The way he had treated us as we grew up, just the hypocrisy was incredible to me. There was also perhaps relief, if that’s the the right word, the idea that my mother committed suicide on my 2nd birthday, I had a lot of rejection associated with that. So there was something healing in a strange way to learn she hadn’t done that.”
Growing up with no memories of his mum, he said “one of the beautiful things” that happened was when his mum’s friend made contact and told him she was a “charismatic, friendly, fun woman” and “how much she enjoyed motherhood”.
Growing up, Seamus said the house was dominated by Colin Howell and his evangelical Protestant beliefs, with “everything framed in a very religious but punitive way”. Saying everything was “just so cold”, he recalled how after dinner, one of the children would be “summoned”.
This would lead to “shouting and screaming” as well as “smacking” if the children had “rebelled against God’s authority”. Seamus told his his father would threaten them with the “umbrella of their authority” and if they stepped outside of that they would be “out of the family”. He says from the age of 10 or 11 he saw his father “as a fake or a fraud”.
Although he considers his stepmother “a victim” too, he says she “100 per cent bought into the Kool-aid of the authoritarianism, the control in the house” and questioned how Stewart could “justify” her behaviour. He said that Lesley was treated like a “dirty word” in their house and that they weren’t allowed to speak of her or even visit her grave.
In 2007 Seamus’ older brother Matthew died in a freak accident when he fell down a stairwell. But it marked the start of Colin Howell’s unravelling, ultimately leading to his confession to the 1991 murders. His son says he was “obsessed” with the biblical King David and felt he was being punished as God punished David.
Friends from church told Seamus of his father’s confession and arrest, meeting him at Belfast International Airport to tell him: “Colin has said he’s responsible for the death of your mum and Trevor Buchanan,” clarifying that it was a murder. Seamus called it a “million feelings at once” as well as a complete “mind f**k”.
He said he received “some cringe letters” from his father after he was detained in 2009 following his confession but that he has not talked to him or visited him in prison, although he said he feels like he “needs to”.
“I don’t know what it means to forgive him, however; I aspire to forgive him. I don’t wish any harm on him. I would really love to hear that he had learned the freedom that comes with being honest and also a little bit of humility.” However in regard to Stewart’s attemps to appeal her sentence, it “goes nowhere”.
He urged her to think whether it’s time to “just accept this” and say sorry. “It’s more than just for me. On a personal level, it’s not going to make a big material difference in my life, but I’m talking about things from the perspective of my mother, and there’s a whole other person there: Trevor Buchanan. I think there could be a value to the community.”
Seamus has returned to his mother’s grave and “thinks about her often” especially on her birthday. She was just 31 when she was killed.
His sister, Lauren Bradford-Clarke said it has been “very distressing” to hear her father’s confession to killing her mother and his lover’s husband. It is the first time the confession tapes of the killer and sex offender have been broadcast in public, as part of a separate BBC documentary Confessions of a Killer. She said hearing Howell’s voice had brought back feelings of “shock, horror and trauma”. “It has been very, very difficult to come to terms with,” she told BBC News NI’s Evening Extra programme.
The documentary ‘Killer in the House’ is available now to watch on on ITVX.
