William Cornick from middle class home who turned into a loner obsessed with zombie video games William Cornick sentenced to life in prison for murder of his teacher The 16-year-old stabbed teacher Ann Maguire in his classroom His parents described as 'loving' and 'devoted to their children' Although parents divorced a decade ago, he had a 'happy home life' By Chris Brooke for the Daily Mail and Paul Bentley for the Daily Mail A clever child from a loving middle class home, William Cornick was the most unlikely perpetrator of a crime that would shock Britain. As the 16-year-old was sentenced to life in prison after becoming the first pupil to kill a teacher in a British classroom, friends said they were stunned by his senseless stabbing of his teacher Ann Maguire. To the teacher in charge of his year he was "a delightful pupil who always gave his best." Fellow pupils at Corpus Christi Catholic College said he was a just a "typical lad" who rarely misbehaved. Killer: William Cornick was 15 years old when he stabbed his teacher Ann Maguire, 61, to death, as she taught a class at Corpus Christi Catholic College, in Leeds, in April "He was probably the most intelligent person I knew," said Tom Smith, a former student. But he was really quiet and kept himself to himself. He had his friends, but he wasn't with them all the time. "You can look at someone and say "I don't think they could do anything like that." I'm still shocked. I didn't think that in a school like Corpus such a thing could happen. Another unnamed student said: "He was like any other lad my age; he wasn't a naughty kid. He was a typical, nice lad. It seems surreal how it's changed. Cornick was no youth from a sink estate left to his own devices by a dysfunctional family. His mother Michelle, 48, is a human resources manager, who was said to be devoted to the teenager and his 19-year-old brother Zack, who is in a rock band. Stable life: Far from being having an unhappy upbringing, Cornick, depicted in a court sketch, comes from a middleclass background and his parents have been described as loving and supportive Their father Ian is a 50-year-old council executive who lives with his partner and their young child in an upmarket village near Leeds. Although his parents divorced a decade ago, Cornick seemed to enjoy a happy home life. Former magistrate Penelope Gibbs, who chairs the Standing Committee for Youth Justice umbrella group of charities and campaign groups, said the sentence was too long. Paul Greaney, prosecuting, said there was nothing to indicate to the boy's parents or teachers that he was capable of homicidal violence. He added that Mr and Mrs Cornick are "decent and responsible parents" who have co- operated fully with the police. Mr Justice Coulson said Mr and Mrs Cornick were "responsible and caring parents and his family life was marked by love and support." Cornick had never been in any trouble with the police and was one of the brightest students at Corpus Christi, passing five GCSE exams a year early. He was regarded as "amicable, enthusiastic and conscientious" at school, with a 100 per cent attendance record. In the four years before the killing, five incidents of misbehaviour were recorded - two minor. Significantly, the final three took place two months before the murder and concerned his hatred of Mrs Maguire and dislike of Spanish lessons. But closer inspection of Cornick's internet use revealed a different side to his apparently respectable image. As one pupil said: "The Grim Reaper was the first thing you saw on his [Facebook] page. That corrected everyone's opinion. [I thought] what the hell has happened, something has definitely gone wrong. Friends had begun to regard him as a "loner and weirdo" and "disturbing" aspects of his personality became apparent. He spoke openly about murdering his teacher, messaging a friend on Facebook about brutally killing her and spending the rest of his life in jail. He had numerous images of knives on his mobile phone. He also had a keen interest in ultra-violent video games, including Dark Souls II, in which players hack zombies to pieces. Players devour the souls of their fallen enemies to the sound of cries of agony. Disturbing images include a character made up of hundreds of human corpses. It was voted one of the ten Most Violent Video Games of 2014. One pupil recalled Cornick saying disgusting things at a party. He said: "He was saying twisted stuff like "imagine jumping on a pregnant woman and seeing the baby come out," and saying horrible stuff about cancer and stuff like that. Loss: Ann Maguire's family, husband Don and daughters Emma and Kerry, stand outside Leeds Crown Court as a statement is read after the sentencing He was just saying it in conversation. He thought it was normal but it's not. He wasn't normal in the head. But for a long time Cornick had been able to hide his "anger" from others by maintaining an appearance of normality. From game to real life: Will Cornick's Facebook photograph shows him wearing a gamer tshirt The teenager later confessed to a psychiatrist that the killing had been on his mind for three years, and one expert said he had engaged in a "considerable amount of fantasy" about killing Mrs Maguire. Psychiatrists decided he suffered from a personality disorder with psychopathic tendencies. It was of course too late, but the danger this previously anonymous teenager poses has now been revealed to all. John Kent, a forensic psychiatrist, said Cornick "presents a risk of serious harm to the public and that this risk is present for the foreseeable future." Mr Greaney told Leeds Crown Court: "One of the most disturbing aspects of an extremely disturbing case is that [Cornick] not only lacks remorse but is proud of what he did in killing Mrs Maguire." The QC said Cornick told a psychiatrist: "I wasn't in shock, I was happy. He added that Cornick's parents were "at a loss" to understand how their son could have committed such a crime. Absolved of any blame by both police and the judge, Mr and Mrs Cornick sat behind their son in the court room dock as details of his chilling lack of remorse were revealed. Gudrun Wroot, who worked with Mrs Cornick at a catalogue publisher, said: "It is awful for the family of the woman who has been killed but it is also traumatic for the family of the boy. Mothers blame themselves but she can't ... It is just terrible. But really she is a nice person and a very caring mother.