"They blame us as musicians because it's easier than blaming family or society." How Brazilian metal legends Sepultura were demonised and scapegoated by the media following the horrific murder of a 12-year-old school girl

On the morning of March 28, 1994, a masked man walked into a second-floor classroom at Hall Garth School, in Middlesbrough, England, and forced a male maths teacher to leave the room by pointing a gun at a boy's head. He then ordered the rest of the pupils to kneel down and close their eyes, produced a knife, and began stabbing the children, telling them, "They have killed me, now they have killed you."

Twelve-year-old Nikki Conroy died almost instantly from multiple stab wounds, while two of her classmates, Michelle Reeve, 13, and Emma Winter, 12, were seriously injured before their attacker was overpowered by two teachers.

In a note found at the murder scene, the killer had expressed his desire to bring terror to the school, writing, "I imagine the deaths of young maidens slain in a room choked with desks."

Two days later, several UK tabloid newspapers ran profiles of the attacker, 29-year-old Stephen Wilkinson, with The Sun describing him as a "Skinhead loner who lived for heavy metal horror songs and computers."

"The skinhead's favourite group is Brazilian band Sepultura, whose blood-chilling titles include Murder, Slaves of Pain, Morbid Visions and Screams Behind The Shadows," journalist Guy Patrick reported. "Some fans of their 'Death Metal' music - named after its obsession with horror and violence - call themselves the Troops Of Doom."

The story also quoted lyrics from Schizophrenia album track Screams Behind The Shadows - "I feel pleasure seeing your agony / It burst my insane subconscious / From life I took nothin' but insults / From death I got irrational pleasure" - as 'evidence' of the band's "mind-numbing music".

In the weeks that following, UK rock magazine Kerrang! was deluged with letters from metal fans, sensitive to the horror of the attack, but furious at how the band had been scapegoated by the tabloids in their coverage off the tragedy.

"I know this a touchy subject," wrote M Peel from Aylesbury, "but it is blatantly obvious that the blame is being pushed onto Heavy Metal, and Sepultura's name is being dragged down. The blame lies not on their 'mind-numbing music', but with the society in which we live."

In the May 7, 1994 issue of Kerrang!, Sepultura frontman Max Cavalera shared his own feelings about how his band was being demonised.

"They blame us as musicians because it's easier than blaming family or society," Cavalera said. "For a lot of people our records are an escape from all the shit in their life.

"A guy freaks out and kills a small child. It's probably because his family never talked to him, the whole neighbourhood never gave a shit about him. He's a lonely and fucked-up guy... It had nothing to do with music."

Asked by Kerrang! if he felt that his lyrics could "trigger an unbalanced individual", Cavalera replied, "No".

"People always ask me why I don't lighten up a little bit with my lyrics," he admitted. "I try to explain that the topics I talk about and write about are harsh. I cvan write about them with more honesty cos of how I grew up in Brazil. I started early with a lot of fucked-up shit. It messed up my head... but I managed to survive through music."

"It's easy for them to call me crazy or violent cos of the job that I do. Why judge me when they don't understand anything about me?"

"For us it was really horrible, especially having kids," Gloria Cavalera, Max's wife and Sepultura's manager, told Kerrang! "But if somebody called me and said that happened to one of my kids, the last thing I would be thinking about was what kind of music does the guy listen to."

In December 1995, Stephen Wilkinson, diagnosed as a paranoid schizophrenic, was sent to Ashworth Hospital, on Merseyside, for the rest of his life.

A jury at his trial at Leeds Crown Court was directed by the judge to return a verdict of guilty of manslaughter on the grounds of diminished responsibility, after four forensic psychiatrists testified that Wilkinson was severely mentally ill.

Years later, in 2014, the Northern Echo newspaper published a feature on the tragedy, speaking to some of Nikki Conroy's classmates about their memories of the day, and how it affected their lives.

One of the young women who spoke to the newspaper was then a forensic nurse, who had come to terms with what had occurred at her school twenty years earlier, and offered an empathetic insight.

"For years I struggled to understand how he could do it," she said, "but now I see schizophrenia on a daily basis and accept that he was not looked after and slipped through the net.

"People will find it hard to understand but I don't blame him for what we went through, I accept he was ill and question why he was allowed to get so unwell that he could commit such a crime.

"I don't feel sorry for him but I think he was neglected and feel the incident could have been prevented if he had the correct care.

"If this incident could bring about anything positive," she concluded, "I'd hope it could bring more awareness of schizophrenia as that could have helped both him and us as we struggled to deal with understanding what happened that day."