Lesley had been stabbed repeatedly and her clothes were stained with semen, so the police knew they were looking for a monster. Fate provided the perfect suspect when 23-year-old Stefan Kiszko came to their attention, accused of indecently exposing himself to two schoolgirls. Stefan was an awkward, overweight and uncommunicative man who still lived at home in Rochdale with his widowed mother, Charlotte. It took not so much a leap as a hop of imagination to cast him in the role of child-killer.
Remanded in custody, Stefan signed a confession to the murder, which he retracted almost immediately. This statement, made by a scared and confused man, formed the basis for the prosecution's case. Kiszko continued to protest his innocence, although his defence counsel, David Waddington QC, tried to persuade him to plead guilty on the grounds of diminished responsibility. Stefan was then sentenced to life imprisonment. On his first night in Wakefield Prison, he was beaten up by six other convicts. As a convicted child-killer, he was the lowest form of prison life; solitary confinement under Rule 43 failed to protect him from further attacks and exacerbated the slow disintegration of his mental health.
Despite a chronic lung disease, Charlotte campaigned tirelessly for her son's release. After years of being stonewalled by police, politicians and the legal system, she finally found a sympathetic solicitor, Campbell Malone, who unearthed vital forensic evidence that had not been presented at Kisko's trial: the semen found on the victim's underwear contained sperm. Stefan was sterile. Malone convinced David Waddington, who had risen through the ranks from QC to Home Secretary, to order a police re- investigation. Finally, 16 years after his conviction, a mis-trial was declared and Kiszko returned home.
"At one point, we were going to call the film Scapegoat, because that's really what it's all about," the film's producer, Malcolm Craddock tells me as we trudge through the glutinous mud to the welcome comfort of a pub. There we are joined by screenwriter Peter Berry and by Campbell Malone, who is acting as a consultant to the production. "I keep suggesting they should call it Delusions of Innocence," says Malone. "The authorities regarded Stefan as a schizophrenic with delusions of innocence."
In the event, the two-hour television drama has been called A Life for a Life, a movie-of-the-week title which fails to convey the delicate, unexploitative approach the film-makers have taken to their potentially sensational subject matter.
"Very shortly after Stefan's release, the Kiszkos received several serious approaches to make a film," recalls Malone. "Charlotte and Stefan were very much in favour of telling the story and I felt they should choose the people to do it. In a sense we auditioned the producers and directors."
Neither mother or son lived to see themselves portrayed by Oscar-winner Olympia Dukakis and newcomer Tony Maudsley; Stefan suffered a fatal heart attack 18 months after his release and Charlotte passed away six months later.
"My impression when I met them was that they were completely bound together," remarks Craddock. "You know how sometimes you meet a married couple who are so dependent on each other that if one goes the other will go very, very quickly." He adds there was nothing "unwholesome" about this mother- son symbiosis, something Berry also stresses when he talks about the time he spent with the Kiszkos while researching the script.
The first time he met Stefan, Berry was confronted by his own prejudices: "I realised that if I had been on that jury, I might have been swayed by the way he looked." Stefan's manner did nothing to assuage the writer's initial discomfort. "I sat down and talked to him and realised he wasn't talking back. He didn't say anything for the whole day. After 10 or 12 minutes, I ran out of sensible things to say and I thought `I've blown this'.
"When I arrived the next day, he stood up and walked out. Then he returned, with the strongest cups of tea in the world, and talked, just a little. On the third day, he was much more open. In the end, one of the difficulties I had was getting the information I needed for the story, without making it too painful for Stefan."
Charlotte was much more forthcoming. "She could talk under wet cement," laughs Berry. "She would talk and talk and talk and talk. She'd say `This is what you've got to get right, Mr Writer!'."
A Slovenian immigrant who came to Britain at 18, Charlotte was used to fighting her corner. Living in post-war England with a Germanic accent and bringing up an odd-looking, socially awkward son made sure of that.
"I'm sure her maternal instinct was in overdrive," says Olympia Dukakis who, when we meet, has just spent two days in hospital with a severe case of flu, courtesy of the inclement weather.
Her portrayal of Charlotte's terrier-like refusal to let go of her son's innocence is the narrative motor of the story.
"As Stefan was growing up, he was an object of ridicule. Charlotte had that kind of peasant mentality where you accept what God has given you, and take on the responsibility for it.
"Of course, that gets interpreted as being a domineering and over-protective mother. But she looked for ways to make him feel good about himself, as any parent would.
"She encouraged his talents for music and languages. And when difficulty occurred, she didn't sit back and take the blows. She did something about it."
Dukakis got involved with the project when Craddock and Whittaker met her at a BAFTA awards ceremony and recounted Stefan's tale. "I was very moved by their passion and their dedication,"she recalls.
"It's really an incredible story. You think, `My God, look at what these human beings went through!' And this wasn't war-torn Bosnia. This was England in the Seventies."
Media coverage of the original case depicted Stefan as a sex-crazed demon. After his release, he was reinvented as a bumbling, simple-minded dupe.
Charlotte deeply resented both portrayals of her son and entrusted the film-makers to redress the balance. Berry recollects how, at Stefan's wake, she took him aside and issued the firm instruction: "You tell the world about my son, how he really was."
The writer believes A Life for a Life may achieve more than the posthumous rehabilitation of Kiszkos's image.
When Stefan walked free in 1992, Lesley Molseed's father and siblings were plunged back into a 16-year-old nightmare. The family expressed their sorrow at Stefan's false imprisonment and have been calling ever since for the true killer to be brought to justice.
Berry hopes the film will result in the case being re-opened: "If the real murderer were found, we would also have done some service for the Molseed family."
Since the verdict on Kiszko was declared unsafe, Campbell Malone has been inundated with requests and pleas to handle alleged miscarriages of justice.
"It's alarming," he says. "If just a tenth of them are genuine, there are a lot of people in our prisons who shouldn't be there. But how do you judge? Do you go by what someone looks like? After all, that is what happened to Stefan."
`A Life for a Life' is on ITV at 9pm on SundayReuse content