'How my work as a death row investigator was turned into a play'

Most authors have day jobs, but mine is quite unusual: I work with men and women facing execution as a death penalty investigator. Sometimes my job is to see if they are innocent – we’ve now exonerated over 250 innocent people off death rows in the United States, so this is not a light question. When they are guilty my job turns to finding out why they did it. It’s a fascinating job, one where I get to learn the answers to what creates violence and how we can prevent it. Being able to help others has been a form of redemption for me too.

Most of my novel was inspired by real-life moments in my work. The idea for The Enchanted came as I was leaving the prison where I work. I was walking to my car when I heard a distinctive voice say, "this is an enchanted place". The Enchanted tells the story of a death row inmate who has chosen to die and has asked to be executed after refusing his appeals. At the time I wrote the novel, there was a case like that in my life. Like the character called The Lady in the novel – an investigator like myself – I wondered if such a wish should be honoured. Should the condemned be able to choose death? What is justice, and is redemption possible even for the worst among us?

I wrote the novel while I was dealing with a death row inmate who had chosen to die

As part of my job, I spend much of my time in the poorest areas, where most of my clients were raised. I find long-lost relatives, school teachers, neighbours – anyone who can teach me about this person’s life. I sit with old women in shacks in the woods, find doctors who saw the client as a child, dig up records in dusty old basements, and more. Each man on death row comes with a story, and my job is to find out that story, and to tell it for the court. All of those characters made their way into the book.

After the novel was published, I was honoured by attention but for me the crowning achievement came when a theatre company called Pharmacy Theatre asked if they could adapt the novel to the stage. I handed over my novel to the playwright, both excited and nervous. Would they honour the spirit and translate the story?

Each person on death row comes with a story, and my job is to find out that story

A few days ago, I came to London and found out the answer. The Enchanted is playing in a wonderful small theatre in south London called The Bunker which has a suitably prison-like entrance. When the lights came up a man was standing in the middle of the stage. His eyes were piercing, and his distinctive voice carried: "This," he said, "is an enchanted place." A breath escaped me: of pleasure and delight.

Sometimes life does come full circle, and what inspires us becomes our creation, and then, in the best of kind of justice, our subsistence. I was immensely honoured to have the company adapt my novel so beautifully so thank you to Pharmacy Theatre, and to the big-hearted people of London, for showing this death penalty investigator and author that life is, indeed, enchanting.

The Enchanted runs at the Bunker Theatre until 17 June.