It is very difficult to anticipate the impact a television documentary will have before it goes out on air. You hope that people will watch and that the views and ideas they encounter will challenge complacency and make them sit up and think.

I worked with the late journalist Mary Raftery for many years, and the first thing I learned was that she never took the easy way of approaching any subject. She wasn’t interested in making programmes that were informative and entertaining: she wanted more. The programmes she made were always aimed at confronting truths about power: who has it and how it is used.

In 1998 we set up office in an old prefab at the back of RTÉ and began work on States of Fear. Mary had been working on the series for many months, travelling around the country and meeting hundreds of people who had spent time in industrial schools. She had the idea for it many years before, and she had frequently gone back to the questions of why so many children were locked away in industrial schools and what the State's role was.

I joined Mary in mid 1998, and we began the task of gathering and structuring a huge amount of research into three 50-minute programmes that were broadcast at the end of April and beginning of May 1999.

States of Fear did something that seldom happens as a result of television. It changed people's minds. It also led to an apology from the taoiseach of the day, Bertie Ahern, to the setting up of an inquiry, to changes in the law, to the establishment of a compensation scheme costing well over €1 billion and, most importantly, to some kind of justice for the victims of institutional child abuse. Denial and complacency were no longer possible.

After the first two programmes we were overwhelmed by the public reaction. Then, on May 11th, 1999, after a cabinet meeting, Ahern called a press conference. Mary and I were still working on the final details for the transmission of the third part of States of Fear, due for broadcast that evening. It contained compelling testimony of abuse in industrial schools right up to the 1970s and 1980s, as well as details of an inquiry into abuse that happened at Madonna House in Dublin in the 1990s; the State had suppressed the inquiry's report.

You couldn't be too careful with material such as this, so there was no possibility of our leaving Montrose to go to the press conference. Like many other people around the country we watched Joe Little's report on the Six One News.

The pressure on the government to act in response to the overwhelming evidence of State involvement in the abuse of children had been mounting. Many opposition politicians were putting pressure on the government to apologise on behalf of the State.

Mary knew this, but we weren’t quite prepared for what happened at the press conference. “On behalf of the State and all of the citizens of the State, the government wishes to make a sincere and long-overdue apology to the victims of childhood abuse for our collective failure to intervene, to detect their pain and come to the rescue.”

Ahern’s words left us speechless.

Now, 15 years later, it is a good time to take stock, look at the legacy of States of Fear and explore how television and film-makers present personal testimony on the small and big screens. What responsibilities do programme-makers have when they present someone's experience to the public? How does it affect the lives of the subjects of such programmes? It is also important to look forwards and to encourage journalists and film-makers to take on difficult issues and challenge complacency in the future.

The Mary Raftery Journalism Fund marks 15 years since States of Fear with screenings and a seminar at the Irish Film Institute next Saturday. Speakers include Patsy McGarry of The Irish Times, Catriona Crowe of the National Archives of Ireland, Colm O'Gorman of Amnesty International Ireland, Sally Mulready of the Council of State, Paul Maguire of RTÉ, and the writer Roddy Doyle