Brian McGilloway: Crime fiction has also been affected by change in Northern Ireland

Despite being born and bred in Derry in Northern Ireland, when I wrote my first novel, Borderlands, in 2003, I chose to make my fictional detective, Benedict Devlin, live in the small border village of Lifford in the Irish Republic and gave him a job as an inspector in An Garda Síochána.

In one way, this was to allow me to observe the North and how it was changing from a remove. However, the most compelling reason for setting the book in the South rather than the North, for me, was that setting the book in Ulster would have meant making Devlin an officer in the Police Service of Northern Ireland. And, in 2003 when I wrote that book, I felt that I couldn't do that.

In part, my reluctance was a consequence of having grown up during the Troubles and the fact that the old police force in Northern Ireland, the Royal Ulster Constabulary, could not have been viewed as an impartial community force, particularly with regards to their treatment of the Catholic community. Claims of collusion were rife and the RUC, by the time of its demise, could hardly be said to have the confidence of both traditions in Northern Ireland. Indeed, such a view was endorsed by the Patten Commission when it suggested the replacement of the RUC with a new Police Service of Northern Ireland, complete with changes of uniform and emblems, a renewed focus on human rights, an emphasis on community policing and normalisation, and, crucially, increased representation from the nationalist community. By 2003, when I wrote Borderlands, the PSNI had replaced the older force and was making attempts to redress the balance of Catholic and Protestant officers so as to represent the whole community.

However, I decided not to make Devlin a PSNI man because I didn't want the novel to be political. Instead I wanted to suggest the change in Northern Irish society by examining normal crimes, albeit, ones happening in the shadow of the previous 30 years - influenced by it, but not part of it. To investigate normal crimes, I needed a normal policeman and, more importantly, a normal police force. And, in 2003, the PSNI was still a force in flux and one that remained firmly on the political agenda in Northern Ireland.

When I wrote the book, Sinn Fein were still opposing the Policing Board meetings in the local towns. I worried that, if the book should ever actually get published, it would be out of date, anachronistic before it ever saw the light of day. So too it proved, for a month before publication of that first novel, finally, in 2007, Sinn Fein finally took their seats on the Board and openly supported the PSNI for the first time.

Furthermore, I was concerned that if Devlin was a PSNI officer, readers might look for a political agenda that wasn't there. The point of the book was to suggest that, post Good Friday, normal, ordinary crime had risen to the surface in the North, either because of the reduction in paramilitary crime and associated punishment beatings, or because the ordinary crimes had always been there, but the newspaper space had been consistently taken up with the more spectacular, and deadly, political violence that bedevilled the country.

Despite this, the Devlin books do have a PSNI character in Jim Hendry, whose relationship with Devlin reflects, for me, how the two forces have begun working ever more closely in tackling all-island crime.

My new book, though, is the first I've written set entirely in the North. It is set in Derry and the main character, DS Lucy Black, is a Catholic PSNI officer. The book touches on some of the difficulties that such officers face, though it is an issue I wish to explore further in subsequent books featuring Lucy. The time to write the book seemed right to me, though. The PSNI seem to be striving to become a community police force. Many young men and women, regardless of religion, are joining and serving their community.

And, as in the case of Ronan Kerr, paying the price for that service at the hands of those who would drag the country backwards rather. Yet, the remarkable sight of Martin McGuiness and Peter Robinson standing side by side, the former attending a police officer's funeral, the latter a Catholic Church service, shows just how far the country has moved in the past ten years. And, sadly, it also highlighted the dangers of moving backwards. The father of a friend of mine was shot when we were children because he was a Catholic police officer. He had joined the RUC in the hope of changing it from the inside, of representing and serving his community. We seem to be moving full circle when young Catholics are being targeted again for serving their community in the police force. Yet the reaction of the general public, the feeling of revulsion that those who claim to represent Ireland would blow up an Irish speaker, a GAA man, a son, on the day before Mother's Day, must surely offer hope that this time things may be different.

• Little Girl Lost, by Brian McGilloway, is published next week by Macmillan, price 12.99