So far, so true, and the first half-hour of a new BBC2 drama, Five Minutes of Heaven, recreates the teenage Little's cold-hearted assassination of Griffin. Then the one-off drama, written by Guy Hibbert (Omagh) and shot by the German director of the acclaimed Hitler drama Downfall, Oliver Hirschbiegel, veers off into "what if" territory. It imagines what would happen if the two men were to meet up now, in deep middle-age, over three decades later. Would there be "truth and reconciliation", as the fashionable post-conflict mantra would have it, or something altogether darker and more volatile?
"The film is about the complex psychological relationship that exists between the perpetrator of a crime and the victim," says producer Stephen Wright from BBC Northern Ireland. "It is not about truth and reconciliation. It is not about finding easy answers."
The real-life Little (played in the drama by Liam Neeson), having spent 12 years in prison for his crime, now works in "conflict transformation", running workshops for traumatised people in Ireland, Israel, the Balkans and South Africa. Or, as the adult Joe Griffin (played by James Nesbitt) bitterly puts it in Five Minutes of Heaven: "He swans around the world telling people what it feels like to kill a man."
Griffin, who was irrationally blamed by his mother for doing nothing to prevent his brother's murder, is presented as a tortured adult – the meaning of Five Minutes of Heaven becoming clear during the long scene in which Little and Griffin prepare to meet each for a TV documentary. However, in real life the two men have never encountered one another, and probably never will. The writer Guy Hibbert is the bridge between them – having worked with them individually for three years in the process of writing the 90-minute drama.
"I would travel from London to Belfast and meet Joe on one day and Alistair on the next day," says Hibbert, who, having been asked to write a drama about the legacy of the Troubles, first got the idea for Five Minutes of Heaven from watching a 2006 BBC documentary series called Facing the Truth. In the programme Archbishop Desmond Tutu brought together perpetrators and victims of murders in Northern Ireland. Little and Griffin were asked to appear on the show, but Griffin declined.
"Joe said that 'if ever I am in a room with that man I will kill him'." says Hibbert. "What happened to them was 33 years ago, so I thought that if ever there was a story to be told about the legacy of the Troubles, it would be this one."
Having made contact with both men, Hibbert began a long, slow and painstaking process of getting to know them in order to create a dramatic scenario in which the two might meet – and what would happen if they did.
"My first question to each of them was 'what if you had accepted that invitation to go on that documentary programme?' Alistair said 'I would go if Joe wants me to go'... Joe said 'Well, I'd take a knife and have my five minutes of heaven', which is the way he put it to me.
"I'd be sitting at the kitchen table with Joe and his partner Sharon and I say 'look Joe if you took a knife and stabbed him what would be the next scene?' – and he said 'you're the writer, you tell me'. I told him that 'your wife and two daughters would be watching TV and there'd be a knock at the door and there'd be a policeman and woman at the door and then we'd cut to the two daughters crying.' I said to Joe I don't want to write that scene...
"Probably the tensest part of the whole project was when I left them in peace for about six months while I wrote the script, and then presented them with it. That was the first time they'd come face to face with each other, if you like. Alistair then found out for the first time what Joe thought of him. For the first time Alistair was faced with Joe's words – and I was the vehicle through which those words came to him. "
Hibbert sent the finished script to Liam Neeson – he hoped he would play Little – just as Neeson was about to start working on The Other Man with Richard Eyre. "I normally never read another script when I'm preparing for a film," says the actor, speaking before the recent death of his wife Natasha Richardson in a skiing accident. "There it was on the bed and I started reading it. It was an absolute page-turner and I called Guy up the second I finished it and said, 'What's the deal here? I'd love to be involved.' I told him my availability and they got it together."
Another fortuitous window of opportunity opened when the German director Oliver Hirschbiegel, who made Downfall, the Oscar-nominated movie about Hitler's final days in the Fuhrer-bunker, became available after a project that he was working on with Guy Hibbert was postponed. "Oliver is minimalist," says the producer Eoin O'Callaghan. "Little fuss, little lighting, little tricksiness. His brain works fast and he anticipates problems." It is also an advantage that he is German, says O'Callaghan, and thus distanced from the events depicted in Five Minutes of Heaven. Not so the stars, Liam Neeson and James Nesbitt – actors from different sides of Northern Ireland's sectarian divide.
"It's interesting that Liam is a Catholic playing a Protestant and I am a Protestant playing a Catholic," says Nesbitt, a teacher's son born in Ballymena, County Antrim. "I felt that as an actor from Northern Ireland there is an instinctive responsibility to tackle the recent history of where we come from." Neeson, a school caretaker's son also, extraordinarily, from Ballymena, agrees with his co-star. "The drama analyses the experiences we've all gone through in Northern Ireland. We may not have witnessed or been part of the violence, but we are all psychologically effected by it."
Where Neeson and Nesbitt differed was over to whether to meet the men they were to portray. Neeson chose not to until the final day of filming. "I didn't want to meet Alistair," he says. "I wanted to rely totally on Guy's script and I knew that he had done vast amounts of research and interviews with those involved. I wanted to rely on that and not get into the situation where I would meet the real Alistair and think 'Oh, I'm taller than him... or 'I don't look anything like him'. "
Nesbitt, on the other hand, wanted to meet the real Joe Griffin from the start. "I've played a few living characters before," he says. "Ivan Cooper, who I played in Bloody Sunday (Paul Greengrass's film of the 1972 Bloody Sunday massacre), for example. The character comes alive for me off the page, but I had the option of meeting Joe and wanted to."
Whether it was spending a lot of time with Griffin, or whether it is the quality of Guy Hibbert's script, this is one of Nesbitt's best performances to date, capturing the nervy, twisted sense of injustice of a man who thinks his life has been destroyed before it even properly began. "Joe was incredibly honest about the events of 1975 and the impact they had on his life and those around him," says Nesbitt. "He was kind enough to let me video him – something I've never done before."
And whatever critics and viewers think of Five Minutes of Heaven (and, for what it's worth, I reckon it is a fine, thoughtful and – given the recent killings in Northern Ireland – timely piece of work) the fact that, thanks to his participation, Joe Griffin is now receiving trauma counselling for the first time makes it, says Nesbitt, "worth doing the film for alone". Does Guy Hibbert, who has spent a lot of time with both men, think that Joe and Alistair will ever meet?
"I wouldn't rule it out but it's not on their agenda," he says. "I first started out thinking this would be about truth and reconciliation and all those rather cliched thoughts. I had a quite a simplistic view, I suppose, although I had done Omagh. But I learned through the process that it's a lot more complicated than those awful simplistic words like 'closure' and 'forgiveness'. It's incredibly tough."
'Five Minutes of Heaven' is at 9pm on 5 April on BBC2Reuse content