WILLIAM Cornick was jailed for life with a minimum of 20 years for the murder of his Spanish teacher Ann Maguire.
The schoolboy, then 15, stabbed his victim to death in her classroom on 28 April 2014. As a new inquest looks into the shocking case, here's what we know.
Who is William Cornick?
William Cornick was born on 26 June 26 1998.
While his parents were separated, Cornick was said to have been raised in a supportive and loving environment.
In court, Cornick was described as appearing on the surface to be "reserved but amicable, enthusiastic, and a conscientious" student at Corpus Christi Catholic College in Leeds.
He was diagnosed with diabetes in 2010, meaning he would not be able to follow his dream of going into the army.
Two months before his 16th birthday, his "completely irrational" feelings of anger towards his Spanish teacher Ann Maguire began to intensify, his murder trial heard.
Cornick told fellow pupils that he wanted to kill Mrs Maguire after she gave him a detention and told him he could not drop Spanish, a later inquest was told.
Before the murder, he wrote to a friend telling him: "The one absolute f***ing b***h that deserves more than death more than pain torture and more than anything that we can understand."
Psychologists described Cornick as having "a gross lack of empathy for his victim and a degree of callousness rarely seen in clinical practice".
One consultant child and adolescent forensic psychiatrist said they could not exclude the possibility that the teen would kill again.
Who was Spanish teacher Ann Maguire?
Ann Maguire was a Spanish teacher who had been working at the Corpus Christi Catholic College in Leeds for four decades.
The 61-year-old was described by her husband Don as a "beautiful, vivacious, caring, generous human being."
The pair had met in 1972, with the couple going on to have daughters Emma and Kerry.
Ann was described by one of her students as "really caring…she sort of couldn’t do enough for people, she was just really lovely to everybody."
Others said that the mum-of-two genuinely wanted to see her students succeed.
A memorial was held for her on 29 September 2014, with an
What happened on 28 April 2014?
Cornick's trial heard that he had been planning to murder his teacher and two others the day before the attack.
He considered using a gun or even pushing Mrs Maguire out of the window.
Cornick did not hide his plans and even told fellow students that he planned to kill his teacher and target another one who was pregnant.
After going to Spanish class with Mrs Maguire, Cornick returned to the classroom and stabbed the teacher in the neck and back seven times.
Mrs Maguire, who was just 5ft 2in tall, then ran from the room trying to escape. She screamed to a fellow teacher that she had been stabbed.
The other staff member then pushed Mrs Maguire into a room and blocked the door so Cornick could not get in.
Mrs Maguire passed out and despite attempts to resuscitate her she was pronounced dead later that day.
What happened next?
Cornick was jailed for life with a minimum of 20 years at Leeds Crown Court on 3 November 2014.
In 2015 the teen lost an appeal against his sentence.
An inquest into the circumstances surrounding her murder held its first hearing on 13 November 2017, almost three years to the day since Cornick was jailed.
Det Supt Nick Wallen, who led the investigation, told Wakefield Coroners Court he felt Mrs Maguire "stood absolutely no chance whatsoever" against Cornick, despite him telling at least 10 other children of his evil plan.
Mr Wallen told the inquest jury: "It would be wholly wrong to sit here and raise that perhaps all this could have been avoided if a 15-year-old boy had told the teacher."
It also heard that Cornick, who listened to Pulp Fiction soundtrack Jungle Boogie in class, had boasted how he would carry out the killing for a £10 payment.
Mrs Maguire's husband, Don Maguire, said he had difficulty accepting the prevailing "narrative" that there was "no explanation and no logic" to what Cornick did, and explained that this was why he had pushed for further investigations.