That concludes our live coverage of the beginning of the trial.

The key points from today are as follows:

• Richard Thyne KC, prosecuting, opened the case against a 15-year-old boy who denies the murder of Harvey Willgoose, also aged 15. He admits manslaughter and bringing a blade onto school premises.
• CCTV played in court showed the boy "dancing on his toes, waving a knife around" after stabbing him in the courtyard of All Saints Catholic High School on 3 February.
• The prosecution said the defendant, who cannot be named due to his age, had an "unhealthy" interest in knives and other weapons, and had been visited by police previously after his mum found an axe in his bag.
• Harvey's death followed an altercation on 29 January at the school, between a friend of his and a friend of the defendant. The school was put into lockdown after the accused said he had seen a knife on one of the boys during the fight. Harvey had not been at school that day.
• Gul Nawaz Hussain KC, defending, said Harvey's death was "wholly unnecessary" and a "tragedy". He said the accused did not set out to kill or seriously hurt anyone, and he lost control after a long history of "bullying, poor treatment and violence".

Thank you for joining our coverage today. Read the full story here.

After the brief back-and-forth, the defendant is seen on CCTV entering the dining area, still holding the knife.

As described by Mr Thyne KC earlier, the CCTV shows pupils running in all directions while he was "dancing on his toes and waving the knife around".

Carolyn Siddall and her colleague Rachel Hobkirk are seen approaching him, with one of them moving her hands up and down in a calming gesture.

Harvey, still on his feet in the courtyard, is seen closing the double doors where the defendant had re-entered the building.

Harvey enters the room for a moment and looks at the defendant, before going back outside, where he collapses to the floor.

A few minutes later, after head teacher Sean Pender escorts the defendant from the scene, the footage shows pupils surrounding Harvey in the courtyard.

The CCTV then cuts off, concluding the evidence for the day.

At 12:10 GMT, CCTV shows Harvey leaving the isolation room, where his head of year said he had regained "good spirits".

He heads towards the courtyard where he is joined by another pupil.

Meanwhile the defendant is seen greeting another pupil and standing in the dining area.

Det Con Middleton confirms their location to Mr Thyne KC as CCTV shows them leave the room at 12:14 GMT.

The boys meet and interact. The defendant pulls out a knife and stabs Harvey, as described by the prosecution earlier today.

About five minutes later, the defendant returns and a further conversation takes place between the pair and another pupil.

They go their separate ways until just before 11:00 GMT, when they interact in the same corridor as before, with many other pupils around.

Mr Thyne KC mentioned this exchange and further pushing earlier today, and asked the jury: "Who is the one who appears he may be trying to provoke something?"

Further CCTV footage shows Harvey leaving the science classroom at about 11:15 GMT, minutes after the defendant arrives, which Mr Thyne KC detailed in his opening statement.

When the defendant leaves the classroom, about half an hour later, Harvey is already in the isolation room where he had asked to go earlier.

CCTV footage shows the defendant standing in the queue for the school's late check-in desk, rocking from foot to foot.

Harvey arrives at school about 20 minutes later, just before 09:00 GMT, with a friend, also captured on CCTV.

Just after 09:00 GMT, the boys speak in a corridor. The defendant pushes Harvey a couple of times at the start of the interaction.

Earlier today, referencing this, Mr Thyne KC said: "You may think that [the defendant] is physically pushing Harvey at times, and you may want to ask yourselves if [he] appears to be trying to provoke Harvey into reacting."

Harvey appears to say something to a passing teacher, who smiles. After the defendant leaves, Harvey stands in the corridor.

As the court resumes, Mr Thyne KC tells jurors they will be shown a 30-minute CCTV compilation setting out the events of 3 February.

The footage starts when the defendant arrives at school, just after 08:30 GMT.

The jury is shown the view of the courtyard which the defendant had before he attacked Harvey.

The virtual map shows the area, pictured in CCTV footage earlier, where the boys went back and forth and where Harvey ultimately collapsed.

The court is taking a short break.

Erica Witherington
Reporting from Sheffield Crown Court

The eight women and four men of the jury are seated in two rows, directly below the public gallery.

They’ve been given files of evidence and have a screen between each pair, on which they’re viewing the videos and images presented to them.

Several of them are taking notes.

The 15-year-old boy in the dock has had his head lowered for much of the past few minutes, so that only the top of his hair can been seen.

Det Con Alex Middleton, the South Yorkshire Police officer in charge of the case, is the first witness to give evidence.

He confirms he was the first major crime unit detective to arrive at the scene on 3 February.

Mr Thyne KC is taking him through a virtual map of the school which was compiled after the stabbing.

The images show police tape throughout the corridors and courtyard.

Det Con Middleton confirms the location of the CCTV cameras, and the corridor and classroom where Harvey and the defendant had interacted earlier in the day.

Gul Nawaz Hussain KC, defending, is putting forward a short statement to outline the defence argument.

He says Harvey's death was "wholly unnecessary", and says the defendant accepts responsibility for the "tragic and lasting consequences" of his actions.

"That is why he has pleaded guilty to manslaughter," Mr Hussain KC adds.

"[He] did not set out to kill or seriously hurt anyone."

He says the boy's actions were the result of a long history of "bullying, poor treatment and violence".

"Things that built one on top of another until he lost control and did, tragically, what you have all seen," Mr Hussain KC adds.

The prosecution has finished giving its overview of the evidence in the case.

Mr Thyne KC says he expects the defence to argue the defendant suffered from a "legal loss of self control" which may make him guilty of manslaughter rather than murder.

"There are a whole number of reasons which suggest quite the opposite of him losing control," he adds.

Mr Thyne KC says the accused deliberately took the knife to school, with it in mind he might use it, and did not listen to a friend who asked him to hand the knife over.

He notes the contents of the CCTV, showing the boys going back and forth, and says this is "not someone who has lost the ability to control his actions".

He says suggesting a loss of control, by its legal definition, is "an attempt to avoid [him] having to accept full responsibility for his actions".

Mr Thyne KC says the defendant had an "unhealthy and apparently longstanding interest in weapons".

He says his phone contained photographs of weapons, including hunting-style knives and machetes, as early as April 2024, which the jury has in front of them.

The teenager's internet search history showed he had looked up "zombie killer knife" and other blades.

His mother had contacted the school in December 2024 after finding an axe in his bag, Mr Thyne KC says.

"[He] maintained that he knew nothing about the axe, and he did not know how it had got into his bag."

Police spoke to him, not to arrest him but to discuss his wellbeing and advise him against carrying weapons, Mr Thyne KC adds.

"Self-evidently, and tragically, however, [he] chose not to heed that advice.

"On Monday 3 February, he searched the internet for a prayer to keep him safe, and selected that hunting knife to take into school with him, carefully concealed but readily available to use."

The court is shown three CCTV clips, each detailing an incident of the defendant being involved in some kind of altercation.

In the first, he punches a computer monitor "so hard it smashed", Mr Thyne KC says.

The second shows an altercation between him and the pupil who he alleged had told him he "would get stabbed", detailed below.

The third shows him "actively involve himself" in the altercation on 29 January, Mr Thyne KC says.

He says the boy shows a "pattern of behaviour, ranging from defiance to the use of physical violence".

Mr Thyne KC says it is "undoubtedly right that both boys had their own personal difficulties".

Harvey's mother had contacted the authorities in May last year, expressing concerns about him going missing and losing weight, he adds.

He had been associating with Sheffield United youth risk supporters, and there were concerns around his mental health, he tells the court.

"His parents had had real difficulties getting him to school - he had sometimes become aggressive with them when they had tried to encourage him to do so," Mr Thyne KC adds.

He says the defendant has a long-standing health problem, and some reports suggest he and his siblings have been malnourished.

"He had told his aunt that he did not feel safe at school," he adds.

The accused was arrested in the head teacher's office and taken into custody, Mr Thyne KC says.

In each interview, he had with him a solicitor and his uncle who was acting as his "appropriate adult".

He did not answer questions in his first two interviews on 3 February, but the following day, he provided a written statement saying a pupil had racially abused him which led to a physical altercation.

The defendant said that, in that altercation, the pupil had shouted at him that he would get stabbed, which led him to bring the knife "for protection".

He also said he received "threatening messages" from Harvey on Snapchat, Mr Thyne KC says.

"I thought he was going to use a weapon or knife against me [in the courtyard]," the defendant's written statement said.

"Without thinking and instinctively I pulled out the knife I had in my pocket and thrust it towards Harvey. I did this in self-defence."

The jury has returned after breaking for lunch.

Mr Thyne KC is due to resume the prosecution's opening statement.

So far today, he has detailed the order of events leading up to the fatal stabbing, the incident itself and the moments just after.

The court is back in session to hear the afternoon's evidence.

The jury of eight women and four men take their place.

Prosecutor Richard Thyne KC will continue to lay out the Crown's case that the 15-year-old is responsible for murdering Harvey Willgoose, also 15.

The accused denies murder but has admitted manslaughter.

Image source, Avalon

The morning's evidence has finished.

The court will restart at 14:15 BST, Mrs Justice Ellenbogen (pictured) instructs.

After being stabbed in the school courtyard, paramedics were unable to resuscitate Harvey.

He was pronounced dead at the scene, the court hears.

A pathologist found the cause of death to have been a stab wound to his heart.

Mr Thyne KC says: "That injury would have required severe force to inflict.

"The knife had cut the hard bone of Harvey’s fifth rib."

After Harvey was fatally stabbed, the 15-year-old boy, who has admitted manslaughter but denies murder, told All Saints school head teacher Sean Pender he had been "carrying the knife for protection".

Mr Thyne KC tells the court: "He said that he was also carrying a knife because of the lockdown incident the previous week, and because he had been followed over the weekend and he was scared of getting jumped outside of school."

The boy said he had been threatened by an "associate" of the boy involved in the fight on 29 January, the prosecutor adds.