Double-killer dentist viewed co-accused as another of his victims

Through the crackle of a cassette tape, the voice of a double-killer is soft but clear; his co-accused and former lover, he says, was another one of his "unfortunate victims".

It is the first time the confession tapes of murderer and sex offender Colin Howell have been broadcast in public, as part of a BBC documentary.

Dentist Howell and his former lover Hazel Stewart were convicted of the murders of their respective spouses – Lesley Howell and police officer Trevor Buchanan which took place in 1991.

For years it was believed the pair died in a suicide pact after discovering their partners' affair, but Howell walked into a police station 18 years later and confessed to the murders.

Lesley Howell and Trevor Buchanan were found in a fume-filled garage

It was a crime that sent shockwaves across Northern Ireland – much has been written about it and it was turned into an ITV drama.

In one episode of Confessions of a Killer, Howell is heard in his interview with police describing former Sunday School teacher Stewart's role in the murders.

"Definitely as a person she was a victim," he said.

"There was a co-operation but arising from, you've told me, I didn't know she had a fear, but obviously it's clear she had a fear and didn't know how to escape from it.

"So yeah she responded and did certain things that she now, at the time had even, especially now, regrets.

"But in terms of the driving force as to why these things happened, she's been a very unfortunate victim of Colin Howell and I regret that."

Howell's daughter, Lauren Bradford-Clarke, has said it has been very distressing to hear her father's confessions.

Howell was sentenced to a minimum 21 years in prison, and Stewart to a minimum of 18 years.

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.

Howell is also heard describing how he reached the decision to confess to the murders almost two decades later.

He said there had been sudden changes in his world, including in his marriage and finances, as well as a realisation about his dental practice – "a sudden inability to function with patients".

Howell, who was a prominent member of his local church in Coleraine, said he realised "as a Christian I was a fake".

"My world fell apart and I walked in here probably believing that this was the only way that I could be real and that it would put right what was wrong, that's why I came and confessed," he said.

Elsewhere in the tapes, Howell can be heard admitting how he had been "involved in intermittent sexual behaviours with patients" at his dental practice.

He was later sentenced in 2011 to five and a half years in prison for indecent assault on five female patients.

Howell and Stewart remained in a relationship for five years after the murders of their partners, and Howell admitted to using drugs from his practice on Stewart, including laughing gas as a relaxant and the injection of a sedative.

On his decision to confess, he said he prayed the consequences would be "bearable to the people who I've said sorry to" and that his justice in the law would be "deserved".

The two-part documentary includes interviews with people who knew the Howells and Buchanans, as well as journalists who reported on the killings.

The first episode of Confessions of a Killer is to be broadcast on Tuesday 20 January on BBC One NI at 21:00 GMT, and then on BBC Two on Thursday 22 January at 23:05 GMT. The programme is also available on iPlayer now.