Tonight’s episode of ITV’s Killer in the House investigates the murders of Lesley Howell and Trevor Buchanan, which the channel also covered in a dramatisation called The Secret back in 2016 – showing just how shocking and gripping the case is.
The case sees Colin Howell confess to murdering his wife, Lesley, as well as Buchanan (whose partner, Hazel Stewart, he was having an affair with).
Here’s everything you need to know about killer Colin Howell and where he is now…
Everyone’s clicking on…Who is Colin Howell?
In 1991, Lesley Howell and Trevor Buchanan, who were both members of the same Baptist church community in Coleraine, Northern Ireland, were found dead in a fume-filled garage.
They were believed to have died in a suicide pact after finding out that their respective partners (Colin Howell and Hazel Stewart) were having an extramarital affair.
In 2009, nearly two decades on from his wife’s death, Howell confessed to church elders that he had killed her and Buchanan and staged this to look like a suicide pact.
Those in his church convinced Howell to hand himself over to the police, which he did – after almost twenty years of keeping his crimes a secret.
BBC
Where is Colin Howell now?
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.
Given his minimum term of 21 years, Howell is still serving his sentence as of January 2026. He is currently serving his sentence at HMP Maghaberry in Northern Ireland and is not eligible for parole until at least 2031.
His daughter, Lauren Bradford-Clarke, shared with Lesley Howell, said last summer that she was considering meeting with Hazel Stewart, who her father continued a romantic relationship with after the double murder.
As reported by the BBC, Bradford-Clarke said of the case, “Following my mummy’s murder, there were five years where Hazel Stewart was very much part of my life, and I very much remember her and remember the time that we had with her.
“It’s very sad in a lot of ways, I saw her as a mummy. I had lost my mum, and I wanted nothing more than to have a mum.”
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Jade Biggs (she/her) is one of Cosmopolitan UK’s freelance writers, working across all sections including entertainment, beauty, body, and sex and relationships. She previously held the position of Features Writer, covering everything from breaking news and the latest royal gossip, to the health and fitness trends taking over your TikTok feed. Jade has a degree in journalism and has been a journalist and content editor for ten years, interviewing leading researchers, high-profile influencers, and industry experts in that time. She is a cat mom to four fur babies and is obsessed with Drag Race, bottomless brunches, and wearing clothes only suitable for Bratz dolls. Follow her on Instagram, Twitter, and LinkedIn.