Dressed in a black hoodie, navy tracksuit bottoms and scuffed trainers, the young boy looks self-conscious as he stands on the makeshift stage.

It's Christmas 2017 at the Pauline Quirke Academy, a drama school in Southport, Merseyside, and the youngsters are putting on a performance for their parents.

In one photograph, shared on the academy's social media pages, the boy, aged 11, stands with a script in one hand as he recites his lines.

In another, his arms are linked with other students as they dance in circles around the room.

He attends Saturday morning classes here along with his elder brother, joining other local children – aged between four and 18 – who share a passion for music, dance and theatre.

But this boy is not like the others. While those around him are animated and enthusiastic, he looks sullen and detached, often positioning himself on the edge of the group. As others pose for the camera his eyes, dark and unsmiling, are downcast.

And these photographs, taken so innocently at the time, are now chilling to behold. 

For as we know just six years later, on July 29 last year, the boy – by now 17 – walked into another dance studio, armed with a 20cm kitchen knife he'd procured on Amazon, and launched a vicious and frenzied attack that left three young girls dead and ten other people injured.

The atrocity wrought by Axel Rudakubana, whose malevolent mugshot has drawn comparisons to the Devil, was the worst targeted attack on children in Britain since the Dunblane massacre in 1996.

This week the Mail spoke to contemporaries of Rudakubana. They say they are 'shocked' by the sheer depravity of his acts but also paint a picture of a boy whose alarming behaviour caused other children to fear him from the start of secondary school.

While Rudakubana's lawyer, Stan Reiz KC, told the court on Thursday: 'Something changed in him when he reached the age of 13', we can reveal there were earlier warning signs. 

According to a former pupil called Jamie, who studied at Range High School in the nearby town of Formby at the same time as Rudakubana: 'He was always trouble.'

Talking exclusively to the Mail, he said: 'Everybody knew him from the get-go [in Year 7]. It was clear and obvious that something was wrong in his brain.

'There were occasions when he had to be held back [by teachers]. He was infamous. People would be scared of him because he was not a good person at all.'

Current and former pupils at the state secondary have found themselves in the spotlight this week after the disturbing revelation that, just seven days before the Southport murders, Rudakubana had plotted to take a taxi to his old school.

It seems he had a grievance to settle, and was dressed in the same green hoodie and surgical mask he wore to the attack a week later. 

Had it not been for his father, who persuaded the taxi driver not to take his son anywhere, this might have been a very different tragic story.

School sources say the office phone hasn't stopped ringing, and a letter has been issued to worried parents to reassure them that the 'safety and wellbeing' of students and staff is its 'number one priority'.

Astonishingly, the source adds, headteacher Michael McGarry had no idea about the incident until it was reported in the media this week – and staff are understandably 'distressed' and 'shaken' by what might have been.

As we know, Rudakubana's parents – Alphonse, 49, a minicab driver, and Laetitia, 52 – had moved to Britain from Rwanda in 2002.

Initially, the devout Roman Catholic couple settled in Cardiff, where Axel and his elder brother, whom the Mail has decided not to name, were born, before moving to Southport in 2013. 

The younger boy, one former neighbour recalls, was 'very quiet, an introvert'; a contrast to his likeable brother who was 'full of mischief'.

In Southport, the brothers briefly went to Holy Family Catholic Primary School, before moving to his parents' first choice: St Patrick's Catholic Primary.

Photographs from the time show both brothers surrounded by friends, wearing the school's distinctive royal blue sweatshirt.

But it was when Axel Rudakubana started secondary school in 2017 that things took a darker turn.

A former pupil called Daisy, who sat next to him in English, paints a picture of him as a troublemaker, frequently taking things 'too far' and having 'shouting matches' with the teacher.

By Year 8, Daisy says, he'd already earned a name for himself; 'doing an Axel' became synonymous for misbehaving in lessons.

But it was no laughing matter. She also recalls the dark, ominous look that would flash across her classmate's face when the topic of women's rights came up.

Another student, Rebecca, described him as a 'bad egg' who had a reputation for making sexist jokes to the girls. 'We stayed away,' she added.

They were right to do so.

Passing sentence, Mr Justice Goose told the court this week that he had deliberately targeted 'very young girls', with the purpose of inflicting 'horrific' and 'extreme' violence.

Unlike his elder brother, whom a school source describes as a 'model student, and a real credit to the school', Axel was 'a loner'.

 Classmates remember a smaller-than-average, socially awkward boy with odd mannerisms. 

He'd bring Lego into school and play with it at the back of class. At home, he was into TikTok and gaming, spending hours on his PlayStation and creating his own football team – Axel Rudakubana FC – on the Leisure League website.

Jamie, who was in the same year as the elder Rudakubana brother, two years above, remembers Axel vying for students' attention. 

'He would get up and sing songs in front of the class,' he recalls. 'Axel liked the attention of others. He liked performing.'

It was shortly after starting at Range High that Rudakubana got into drama. A spokesman for the Pauline Quirke Academy confirmed that he attended for several months between November 2017 and February 2018.

During this time, the spokesman adds, there were 'no records of any inappropriate behaviour'.

In late 2017, he was pictured on the academy's Facebook page receiving its 'Performer of the Week' award. The photograph has since been taken down.

Around the same time, he joined Ology Kids Casting, a talent agency based in Ormskirk, Lancashire, co-run by Laura Beckford, the wife of former Everton footballer Jermaine Beckford.

It was through Ology that Rudakubana – described by the agency as a 'superstar' – got a part in an advert for BBC's Children in Need, shot in nearby Blackpool in 2018, in which he's seen emerging from the Tardis, dressed as Doctor Who.

In addition to this video, the Mail has uncovered two more adverts from the same nationwide fundraising campaign, featuring Rudakubana, then 11, alongside other child actors.

Knowing what we know now, they are difficult to watch.

In one, he offers tips for organising a 'movie marathon' with friends, and is filmed sitting on a sofa with two young girls on either side of him. The three are wrapped in a blanket, eating popcorn.

In the other, a promotion for Pudsey Bear merchandise, he's wearing a yellow bobble hat, a fixed grin on his face as he urges viewers to 'Wear these things' in support of Children in Need.

BBC sources have stressed that Rudakubana 'never had an affiliation' with their fundraising campaigns, and have now deleted all of the videos out of respect for his victims and their families.

Back at school, pupils at Range High recall classmates 'taking the mick out of him for being in an advert'. 'I think that annoyed him,' says one.

But as his lawyer claimed in court, around the time he turned 13, Rudakubana 'became more detached and reclusive'. He had, Stan Reiz told the judge, 'a level of maturity that fell far below his age'.

Then in October 2019, Rudakubana, who'd recently started Year 9, suddenly launched an attack upon one of his classmates midway through a lesson.

In a smartphone video, which has been widely shared online, he can be seen kicking and flailing his arms as he is restrained by other students.

There was, a school source says, a bullying incident.

The school has no record of an ongoing complaint, suggesting it may have been a one-off or even fabricated, but a spokesman says Rudakubana accused a classmate of making racist remarks.

'I didn't witness any racial bullying... but I can see how he could be racially bullied at school,' says former student Jamie. 

'There was not a lot of diversity in the school and it's a predominantly white community.' 

Another classmate says his rage seemed to come out of nowhere: 'It must have just got to him and he flipped.'

Rudakubana was sufficiently angry, it seems, to tell the headmaster he was going to bring a knife into school. He later claimed to have done so on ten occasions. 

He also phoned Childline, telling them about the knife and asking: 'What should I do if I want to kill somebody?'

The nature of what he'd said was so serious that Childline contacted the local authorities.

School sources say there is no evidence he ever did actually bring a blade onto the premises while still a pupil, but the threat alone was enough to get him excluded and then expelled.

'It all happened – him kicking off in class, the knife threat, the call to Childline – within a matter of days,' a source tells the Mail. 'He was expelled by the end of the week.'

That, as far as Range High School staff and students were concerned, was the end of it.

Former pupil Jamie recalls: 'I remember thinking it was a safer place if he was not walking around the corridors.'

The police were notified and, at this point, children's social care services at Lancashire County Council became aware of Rudakubana. He was given 'early help' around his 'emotional wellbeing and behaviours', and an autism diagnosis followed later, which led to an 'education and healthcare plan'.

But Rudakubana, it seems, was already beyond help. Plotting revenge against the pupil he'd accused of bullying him, he returned to his old school in December with the intention of carrying it out.

Wearing school uniform and armed with a hockey stick, on which he'd reportedly written the names of those he intended to harm, he went on a 'rampage' through the building.

The uniform helped him blend in; he jumped over the gates and is even said to have attended assembly before he was spotted.

The Mail has spoken with the parent of the girl who saw him and who, alarmed by his unauthorised presence and erratic behaviour, reported it to a teacher.

When cornered, Rudakubana lashed out with the hockey stick, striking a student – not, the Mail understands, his intended target – in the head and badly injuring him, breaking his wrist.

The deputy headteacher then tackled him before dragging him out of school. 'It was a scary time,' Jamie told the Mail. 'It was bizarre and crazy and came out of the blue. I know the person he assaulted and it affected them quite a lot psychologically and physically. It was just the first person that Axel came across.'

Disturbingly, this week it was revealed Rudakubana had concealed a kitchen knife in his backpack that day, though he'd made no attempt to use it.

After the incident, he was referred to counter-terrorism scheme Prevent. Teachers, it turned out, had caught him researching school shootings in the US, with which he'd developed a fixation, during an IT class. He would be referred twice more in 2021.

Soon afterwards, the Covid-19 pandemic hit. Isolated, friendless and increasingly influenced by material he was viewing online, he developed a fixation with dictators such as Genghis Khan and Adolf Hitler, and started reading about the IRA.

'Lockdown really changed him [further],' says Jamie.

By now outside the mainstream education system, he was enrolled at The Acorns School in Ormskirk, a pupil referral unit, until May 2021, followed by Presfield High School and Specialist College in Southport, from March 2022.

A source at Presfield, which caters for young people on the autism spectrum, says he was an incredibly difficult student.

'He attended for less than one per cent of the time,' the source says. 'He received educational visits at home, during which staff tried every trick in the book to rein in his growing obsession with murderous historical figures.

'They'd ask him, 'What about the evil side of things, what about the victims in all this?' There were so many attempts to reach him.'

Staff often asked police to attend their visits to the family home, such was their discomfort at being in his presence.

In March 2022, as we know, he was found in possession of a kitchen knife on a bus. He told police he wanted to stab someone, but was just returned home, with advice given to his mother about securing knives in the house.

What happened next, just two years later, remains beyond anyone's comprehension.

Like others in this community, Jamie, who still lives in Southport, says he feels scarred by having been in such close proximity to the now-notorious killer.

'When I saw his mugshot photo I could not believe how much he had changed,' he adds. 'He did not look like the small kid from Range High School.

'He looked like a complete monster.'

Classmates' names have been changed to protect their identities