Inside: The mind of a killer
Colin Howell is serving a life sentence at Maghaberry Prison, where he has been translating a special braille version of the Bible.
That's at the opposite end of the spectrum from what put him behind bars – the premeditated murder of his wife, Leslie, and Trevor Buchanan, the husband of his lover and co-conspirator Hazel Stewart.
Howell staged the deaths to look like a suicide pact, with the victims' bodies found in a fume-filled car in Castlerock in May 1991.
It remained secret for nearly two decades, until guilt-ridden Howell confessed all and both parties got life sentences.
That he had so much to hide perhaps explains Howell's caginess when I arrived on the doorstep of his Castlerock home on May 2, 2007.
It was a beautiful, warm sunny day and, although I had no idea about Howell's past, I was nervous when I drove up the gravel path.
That's because Howell's eldest son, Matthew (22), a language student, had plunged 40ft to his death from a Russian apartment block just two days previously.
I was there on what the media calls a 'doorstep'; to speak to a grieving family about their lost loved one.
It was the dentist's second wife, Kyle, who let me in – after obtaining permission from her husband – and I was struck by the tall, blond, American woman's beauty.
Howell, who is now 54, seemed to me very ordinary-looking by comparison.
I was taken to a room with bookshelves and a desk with a computer, in front of which he sat, his piercing blue eyes glued to me.
It was just him and me. Normally, the journalist asks the questions, but over the next hour Howell subjected me to a barrage of them.
How did I hear about his son? Who had sent me? What sort of a journalist was I?
He was receptive, his manner curious, but I put it down to grief.
Bereaved people can act out of character.
At the end of our talk, he typed out a statement and, adamantly, warned me not to deviate from it when writing my story.
Six years on, I still remember that encounter clearly.
Long before Howell became daily front page news, I told people about the uncomfortable encounter with that cold, controlling man in Castlerock.
And I'll never forget what he said about his son: "He brought honour to our family."
There isn't much honour left now.