Erica Witherington
Reporting from Sheffield Crown Court

Earlier, Harvey’s parents had been sitting next to each other in the public gallery - both keeping very still, barely shifting in their seats as the Crown opened its case.

After the short break, however, Mark and Caroline Willgoose (pictured above) did not return to their places.

So they were not here as the court was played CCTV, clearly showing the moment when their son, Harvey, was stabbed.

The rest of the family did retake their seats though.

Most had hands to their faces in anticipation, covering their mouths, some still peering at the screen, others shielding their eyes.

Over otherwise shocked silence, several loud sniffs could be heard as the video was played through twice.

A row in front, the defendant’s family members sat with their arms folded.

In the dock, the defendant looked downwards.

Prosecutor Mr Thyne KC says further CCTV footage, which is due to be played later today, shows the defendant go into the cafeteria area with what has been described earlier as a hunting knife.

"Unsurprisingly, other pupils fled in fear and panic, and told members of staff what had happened," he says.

"[The defendant] was dancing around on his toes and waving the knife around, although by this stage he seemed to be saying 'I’m not going to hurt anyone'."

Meanwhile, headteacher Sean Pender ran in from the field to the courtyard to find Harvey receiving help from other staff members.

Mr Thyne says Mr Pender reached the dining room and told the defendant to hand over the knife, to which he replied "you know I can't control it".

“I’m not right in the head. My mum doesn’t look after me right. I’ve stabbed him," he told Mr Pender, the prosecution says.

The jury is shown footage of the accused and Harvey Willgoose separately making their way to the school's central courtyard for their lunch break.

In it, you can see the defendant draw a knife on Harvey and stab twice at his torso.

Harvey then backs away quickly across the courtyard, with the accused following him.

Then, Harvey moves towards the defendant, who had been walking away with the knife still in his hand.

The boy turns and begins bouncing on his toes and "brandishing" the knife, Mr Thyne says.

Within less than a minute of being stabbed, Harvey collapses to the ground, he adds.

Earlier in the opening, Mr Thyne KC said the defendant had explicitly told a teacher he did not have a weapon that day.

At about 09:15 GMT, while discussing the rumours a knife had been brought in the week before, the assistant headteacher had asked the defendant if he had "brought anything he should not have", like a weapon.

The teenager told him he had not.

We have restarted after a brief break.

Conflict began to appear between the boys, who were still siding with their friends involved in the altercation on 29 January, at about 11:15 GMT in a science lesson.

Harvey asked to take a time out when the defendant arrived, and the two ended up "squaring up" to each other, Mr Thyne KC says.

Teacher Sophie Heath-Whyte described them saying to each other, "come on, let’s take this outside".

Harvey left the room and went to see the assistant head of year, Ms Staniforth, and told her he was "upset that [the defendant] had pushed him in the chest".

The prosecution says Harvey asked to go to the isolation room where, after a short while, he "seemed to be in good spirits again" according to Ms Staniforth.

The defendant, who went to see her afterwards, admitted what he had done "but shrugged it off", the prosecutor adds.

CCTV shows the pair together in the school corridor, along with other pupils, at about 11:00 GMT on 3 February,

Mr Thyne KC says one of those pupils describes them "pushing one another and saying 'come on'", which he thought was "just banter".

The prosecutor asks the jury: "Who is it who starts pushing the other? Who is it who demonstrates boxing in front of the other? Who is the one who appears he may be trying to provoke something?"

The CCTV shows the defendant walk away, alongside another pupil, after the interaction.

The court is now taking a break, with the prosecution opening due to resume in about 15 minutes.

The two boys had been in contact on the morning of 3 February, the court hears.

Harvey asked the defendant, "is it beef [or] what"?

A few messages later, the defendant replies "nah but if [you want] beef we can hav it".

Both boys arrived late on 3 February, separately, and booked in at the late desk.

CCTV played to the court shows the pair having a conversation in the corridor at around 09:30 GMT.

The prosecution tells the jury: "You may want to ask yourselves if [the defendant] appears to be trying to provoke Harvey into reacting."

Harvey, 15, had frequently been absent from school and had not been in school on the day of the earlier incident, the court hears.

He had attended school on just 20 days since the start of the academic year.

On 31 January, two days after the false alarm detailed below, Harvey texted his dad to say "am not going in that school while people have knives," the jury is told.

Erica Witherington
Reporting from Sheffield Crown Court

Image source, PA Media

The 15-year-old defendant sits behind the glass panels of the dock, wearing a white shirt, open at the collar.

Close alongside him - a woman who’s acting as his intermediary, assigned to him by the court.

Occasionally they exchange brief whispers.

The boy’s gaze moves around. Sometimes he looks down, sometimes towards the barrister in the well of the court, outlining the case against him.

Briefly he glances up towards his family, sitting high in the public gallery.

The prosecution says Harvey and the defendant "had been on good terms" until an argument on social media on the weekend of 1 and 2 February.

It was sparked by an argument between two other boys, on 29 January.

Police, who searched a pupil after the defendant said he had seen him with a knife during that incident, found no weapon.

It sparked a lockdown at the school on that day.

The 15-year-old defendant admits that he stabbed Harvey and caused his death, the prosecution states, but he says his actions amount to manslaughter, not murder.

"The issue that you will be focusing on in the course of this trial is whether this was, indeed, murder as the prosecution say it was," Mr Thyne KC adds.

The teenager also admitted bringing a blade onto school premises.

The only thing the jury must decide is whether the defendant committed murder or not.

Erica Witherington
Reporting from Sheffield Crown Court

Suspended high up, along one side of Court One, are two rows of the public gallery.

On the first row, family members of the defendant look down on proceedings.

Behind them sit members of Harvey’s family. They are listening intently to Mr Richard Thyne KC, as he details the injuries inflicted on Harvey that day at school.

One lady takes off her glasses to dab her eyes.

Richard Thyne KC, prosecuting, is opening the trial.

"It was just five minutes into the school lunch break, when Harvey Willgoose was stabbed to death," he says.

"A knife was thrust into his chest, penetrating his heart. In less than a minute he had collapsed onto the ground, where he lost consciousness and died."

He says the 15-year-old defendant stabbed Harvey using a 5in (13cm) hunting knife with a serrated edge.

The incident took place in the courtyard at All Saints Catholic High School in Sheffield, Mr Thyne says.

Mrs Justice Ellenbogen warns jurors not to discuss the case with anyone who is not on the jury.

“You are the judges of the fact, and that job is yours exclusively,” she says.

“Those people, whose opinion you would ordinarily value… must not be asked what they think or allowed to express an opinion about the case.

“You must not speak to anyone about what you hear in court."

She asks them not to carry out any "independent inquiries" such as visiting locations mentioned in the trial or reading news articles.

"You should know that jurors have been sent to prison for not obeying the rules I have just been through. It is contempt of court," she adds.

Before we hear any evidence, the judge is addressing the jury.

“The defendant is a teenager, and the trial will be adapted to account for that,” Mrs Justice Ellenbogen tells them.

“Considerable research shows young people should not be treated in the same way as adults … [some questions] can be linguistically difficult for young people to understand.

“Questions might differ in nature and form from what you might have expected.”

She says defence barristers may not “forcefully examine” the young witnesses in the same way as they would adults.

Harvey Willgoose, 15, was described as a “lovely lad” with a “bubbly personality” in tributes left outside the school after his death.

The CEO of the academy trust which runs All Saints School described Harvey as an "immensely popular young man with his fellow students and teachers alike".

Hundreds of mourners attended Harvey’s funeral, which was held at Sheffield Cathedral a fortnight after his death.

His coffin was draped in Sheffield United’s colours and a rendition of a club chant, The Greasy Chip Butty Song, played out the service.

Image source, Family Handout

The trial will be overseen by judge the Honourable Mrs Justice Ellenbogen.

Richard Thyne KC will be prosecuting for the crown, while Gul Nawaz Hussain KC will act as defence counsel for the 15-year-old accused.

When reporting from courts, we often use the suffix KC.

This is short for King's Counsel.

The people with KC after their name (formely QC when Queen Elizabeth II was monarch) are barristers or solicitor advocates who have been recognised for excellence in advocacy.

Harvey Willgoose was stabbed in the chest at All Saints Catholic High on Granville Road just after midday on 3 February.

Image source, Tom Ingall/BBC

A 15-year-old boy, who cannot be identified for legal reasons, was arrested a short time later.

The defendant admitted manslaughter but denied murder at a hearing on 28 April.

He also pleaded guilty to having a blade on school premises.

He was remanded into youth detention custody ahead of this trial.

Chloe Aslett
BBC News, Yorkshire

Good morning and welcome to Sheffield Crown Court.

The trial of a 15-year-old boy for the murder of Harvey Willgoose in Sheffield is due to begin shortly.

Final preparations are taking place in Court One.