In 1994, in Trondheim, five-year-old Silje Redergard was beaten to death by two little boys. Today, the girl's family still suffers and one of the boys is in trouble again – the echoes of the Bulger case are clear. So why has the public reaction in Norway been so startlingly different?

On the afternoon of 15 October 1994, three young children, a girl aged five, and two six-year-old boys, were playing on a football field covered in freshly fallen snow. Their parents were neighbours who did not know each other, but the children had played together before. The three had been making "snow castles", until the fun stopped. Nobody knows why. A childish disagreement? A tantrum, perhaps? Whatever it was it triggered a reaction in the boys that devastated a family and the community. At some point while playing, the boys turned on the little girl, punching and kicking her and beating her with stones before stripping off her clothes. Then they ran away, leaving her to die in the snow.

"Today, I'm tougher than I was when it happened. I've been able to put things in perspective. I've had my chance to mourn," says Beathe Redergard, the mother of Silje, the girl who was killed so close to her home, in a suburb of Trondheim, Norway.

"We didn't know that anything was wrong until a local boy came by and told us," Redergard says. "He was the one who first told us what had happened. He was only eight-years-old, so we didn't know whether he was telling the truth. We went over towards where it had happened and saw a group of police officers. We were stopped and couldn't get to Silje." The police, she says, had cordoned off the area.

"They asked us who we were, and then they put us in a police car and drove us to the station. We were interviewed. It looked like the murder could have something to do with sexual abuse because she was undressed, so the suspicion falls on the closest family members. We were at the police station for a long time. Afterwards, we were driven home. It was almost 10pm."

Redergard, now 43, and Silje's stepfather, Jorgen Barlaup, 42, assumed that the real killers, when found, would be adults. It wasn't until the following day that they discovered the truth, and in the most shocking manner.

"One of the people who'd tried to resuscitate Silje, we went over to her house to say thanks. We thought we should thank her for trying," says Redergard. Barlaup explains what happened inside the house. "The woman told us that she'd done so much to try to save Silje. I was sitting with her son on my lap. Then she said it was him and another boy that had done it. "I looked at the boy and asked him, 'What did you do?' He said, 'I jumped on her because I thought she was sleeping.' Then he said he took off her clothes because he thought she was sleeping. When we found out he had done it, we left. It was too difficult. I wanted to throttle him and be done with it. When I realised that I almost wanted to kill him, we left."

The case of Silje Redergard is often compared to that of James Bulger, who was beaten, tortured and killed by Robert Thompson and Jon Venables after they took him from a shopping centre in Bootle, Liverpool, 20 months earlier.

There were significant differences, of course. James's killers were four years older than the boys who killed Silje; James was three years younger than their victim. The three Norwegian children knew each other and were playing, whereas Thompson and Venables were strangers who stole James away from his mother. And in Trondheim there was no CCTV image such as the one that would become etched in our national psyche.

But perhaps the most significant difference was that, in Britain, the authorities decided to let the nation judge the child killers. Trying Thompson and Venables as adults and releasing names and mugshots unleashed a countrywide roar of anguish that can still be heard today – much to the disadvantage of any damaged child who behaves badly to another, and who needs help rather than "justice". What Silje's story demonstrates is that it needn't have been that way.

"At first there was a lynch mob atmosphere [in the town]," her mother says. "Everybody wanted to know who had done it. Once we got to know that it was these little boys who'd done it, that lynch mob mood died down." Beathe Redergard says she "felt bad" for the boys even in the middle of her grief, because they were "just little kids".

Why two little boys should have inflicted such terrible violence on a playmate will never be known. "We beat her till she stopped crying," one of them later told the police, a clue perhaps as to why the viciousness of the attack escalated, but not as to why it should have occurred in the first place.

Everyone agreed that something must have been out of kilter psychologically. There were reports that one of the boys had been sexually abused before the attack. Nobody said the boys were evil. Neither were they branded criminal – and nor would they have been, even if they had been the same age as Thompson and Venables, who were both aged 10 when they killed James. In Norway, the age of criminal responsibility is 15.

The death of a child at the hands of other children is rare, and of huge national interest wherever it occurs. In Trondheim, Norway's third largest city, 500km north-west of Oslo, there had been just two murders in the previous six years. What happened to Silje Redergard could have been the news event of the decade. But in contrast to the vengeful rage of the popular press in the UK towards the Bulger killers, there was no sensational reporting of her death in the Norwegian press.

On the day after Silje's body was discovered there were no pictures or descriptions of her in Norwegian newspapers, neither did they give her name. The names of the boys, too, were never revealed to the public – and their anonymity has been protected and respected to this day, even though many people (not least Silje's parents) know who they are.

Harry Tiller, the journalist who covered the story for the Adresseavisen, Trondheim's biggest selling newspaper, explains why. "In the local community, everybody knew who these boys were. That was the big difference between Norway and England, that the names were never mentioned [in the press]. It was never an issue to identify them at any level. We have some debates in Norway about identifying criminals, but when it comes to children, it's never an issue. It was never discussed in the newsroom. They were six-years-old, but even if they were 11, it would not have been an issue."

The various professionals involved in the case were at pains to calm the local community. In the days after the killing, meetings were convened in the local school for parents and children, which were attended by police officers and psychologists. Information was disseminated quickly, and professional support was offered immediately. The efforts made to contain the tragedy were huge.

Within a couple of weeks the two boys were enrolled in another local infants school. Speaking in 2001, Trond Andreasson, the head psychologist involved in Trondheim's child services agency, recalled the meetings that he held with the parents whose children they would be joining. "We explained that these boys would start there and what we would do to keep everybody safe," he said. "The parents of the other children accepted this situation and a lot of parents thought that these children needed to be in the kindergarten and needed to be taken care of."

Aase Prytz Slettemoen, who managed the caseworker responsible for supervising the care of the boys for eight years after Silje's death is clear about Norway's policy of avoiding the criminalisation of the young. "We don't believe in prison for youngsters," she says, "so we think that if we can help them in any other way, that's what we should do."

Clearly, great care was taken to ensure that the two boys were protected rather than punished. The boys are now 21. Prytz Slettemoen is adamant that there have been no serious problems. "Neither of them have been involved in violence or criminal activities. They've done quite well," she says.

In Norway, child protection services maintain their relationship with troubled children until they reach 18. At that point they are considered to be adults and are given the choice of making their own way, or maintaining contact with the children's agency up to the age of 23. After that they may choose to maintain a relationship with adult services."

Prytz Slettemoen would not say whether either of the boys had taken that route. "When they are 18, they are grownups in the eyes of the law, so then they can say 'No, thank you' if they don't want help anymore. If they say no at 18, we can ask them again at 19 if they're sure. They don't always know what's best when they are 18."

Nothing is known about one of the boys who killed Silje, but there is evidence that, despite interventions by teams of professionals, the other boy – the one who sat on her stepfather Barlaup's lap, the one he wanted to "throttle," – continues to struggle psychologically with the consequences of his actions. Margareth Rosenvinge works in a Trondheim branch of Kirkens Bymisjon, a mission connected to Norway's state church.

Rosenvinge says the boy has been coming to the mission for about a year or so. "I'm in touch with him pretty much every day," she says. "He doesn't have a home. He stays with friends or sometimes out on the streets with other drug users. He'll sleep one night here, one night there. Sometimes he sleeps in the church."

How much does she know about his life? "I just know he's been involved with child protection services and he had such traumatic experiences as a kid," she says. "He's self-medicating, using alcohol, pills and amphetamines. Life is too hard, and the drugs let him relax. It helps him deal with the everyday. There's no joy in his life ... He's still a young man, but he has no life. He's literally living in a nightmare."

Does he ever cause trouble at the mission? "He's very reserved," she says, "a very nice and calm boy. He seems careful and shy. He never causes trouble. A lot of the guests here at the church mission lead a life of drugs. They can be a big challenge for us to handle, but he's never caused any problems."

The legacy of Silje's killing runs deep for her family, too. Not a day passes when they do not think about her, says Barlaup. And what do they think of the two boys who killed her now? "We've forgiven them for being children," he says, "but we'll never forgive them for what they did, if that makes sense ... If we'd gone around hating children afterward, we wouldn't be able to love our own children, and we remember Silje best by loving our kids. I mean, Silje won't come walking through the door."

Redergard's sympathy for her daughter's killers has lessened over the years. "It's really hard. When it happened, the fact that they were just kids – it was hard to understand that little kids could do something like that. Afterward, I've run into [one of the boys] in town. He'll run up to us and say, 'I'm sorry, I'm sorry,' but it doesn't help."

The impact on Redergard and her family has been enormous. "Not long afterward we moved to another part of town ... basically to the other side of town. It was a little too hard to stay in the same place. If we stayed there, we'd risk running into [Silje's killers]. Now, we're separated from them by the E6." The way she speaks about the E6, a multilane highway, brings to mind some kind of moat, an impassable barrier that will keep out the past. Redergard has had another child, too. Thomas, who will turn five this year, was born more than a decade after Silje's murder.

But nothing could shield Silje's elder brother and sister from the impact of her death. "My kids have had their own psychological problems because they miss their sister," says Redergard. "My son was two-years-old when it happened. Now he's 17 and he still finds it difficult. At one point, he even ran into one of the boys in town ... He found that really hard. And my kids have had a hard time at school. My eldest daughter who was old enough when it happened to understand – she's needed a lot of help. She and Silje were really close. It was almost like they were one person. They were only a few years apart. It was like she lost half of herself.

"You know, when Silje walked out the door that day she told us that she loved us. That was the last thing she said to us, 'I love you.' It was weird. She usually would tell us that when she was going to bed, but not when she was going out to play. It's like it was fated."

That Silje's family should continue to feel the pain of her loss so deeply all these years later is no surprise. That the boy who killed her should bear the scars despite the efforts to help him is also to be expected, perhaps. But what is strange – at least to British eyes – is that the people of Norway appear to have forgiven and forgotten. The debate has been had and people have learned what they can. In Britain, the outcry over the Bulger case is still in full voice, with crowds baying for Venables' blood.

When asked how she thinks the response to her tragedy in Norway compares to how the UK responded to the that killing, Redergard is surprisingly circumspect. "The system we have in Norway is still best," she says.