
A teenage boy accused of murdering a fellow pupil at their school had been interested in knives since the age of 13, a court heard.
Harvey Willgoose, 15, was stabbed to death during his lunch break at All Saints Catholic High School in Sheffield on 3 February.
The defendant, also 15, has admitted Harvey’s manslaughter but denies murder and lawyers gave their closing speeches to the trial at Sheffield Crown Court earlier.
Prosecuting, Richard Thyne KC said the attack on Harvey was “purposeful aggression” and an “act of retribution” after the boys had taken opposite sides in a dispute involving other pupils.
Mr Thyne added that the boy, who cannot be named for legal reasons, “wanted to show he was hard” and had become “obsessed” with weapons in the lead-up to Harvey’s death.
The teenager said he did not remember the attack and that he lost control of himself.
Mr Thyne said the defendant had ordered the hunting knife he used to kill Harvey before a previous falling-out with Harvey and his friend, and was someone with an “unhealthy interest in weapons” who had talked about “shanking” someone when he was 13 years old.
He told jurors the defendant had posted videos on social media with weapons, which he admitted posting because he “wanted some people to know he carried a knife” and “wasn’t someone to be messed with”.
Mr Thyne told the court the defendant had also researched rage rooms and, just over a week before the fatal stabbing, searched “waiting for someone to swing so I can let out my anger”.

The prosecutor told the court that in footage of the fatal attack on Harvey, the defendant could be seen unzipping his coat, putting his hand in his pocket, and taking out the knife.
“He was acting with thought, with purpose and knew exactly what he was doing,” he told jurors.
Starting his closing address to the jury, Gul Nawaz Hussain KC, defending, said the defendant “snapped” after years of bullying and “an intense period of fear at school”.
He told jurors: “Tragically, Harvey was a combination of being the final straw that broke (the defendant) and the unintended face of a series of threats of violence and bullying he had suffered in recent months.
“We say he suffered a loss of control which resulted in horrific and tragic consequences.”
Mr Hussain said: “It is a frightening state of affairs that boys and young men think the way to stay safe is by carrying a knife.
“It’s like a nuclear arms race, and all that happens is the likelihood of them being used increases.”
The trial continues.