THIS is the moment a smirking killer bought a shotgun just hours before he murdered his mum and two siblings in cold blood.
Nicholas Prosper gunned down his mum Juliana Prosper, 48, brother Kyle Prosper, 16, and sister Giselle Prosper, 13, at home in Luton.

Nicholas Prosper smirked after picking up the shotgun he used to kill his family[/caption]
He had shaken hands in a car park as he bought the weapon[/caption]
Juliana Prosper and her two children Kyle and Giselle were found dead inside their home[/caption]
Prosper has been jailed for murdering his family[/caption]
The 18-year-old was captured on CCTV calmly purchasing the shotgun he used in the horror.
Prosper had met a man in a busy car park on September 12, who as seen waving to him as the killer approached with a large bag.
They then shook hands before the teen picked up the huge weapon from the boot of the man’s car.
Prosper was then captured chatting in a lift as he clutched the shotgun just hours before the rampage.
At one point, the sadistic teen placed his head against the wall and smirked as his warped fantasy fell into place.
Despite his age, Prosper had become a member Gun Trader UK, an online marketplace for the sale of shotguns and rifles, in April 2024.
The teen began hatching his barbaric plan by researching how to fake a firearms certificate.
He then offered the gun enthusiast £600 for a shotgun and cartridges – £150 more than the asking price.
The seller was “deceived” by his “high quality forgery” of a shotgun licence”, the court heard.
Prosper is being sentenced today after pleading guilty to three counts of murder.
He also admitted a number of other offences – including possession of a shotgun with intent to endanger life, possession of a bladed article in a public place and purchasing or acquiring a shotgun without a certificate.
It can now be revealed that Prosper had a sick desire to carry out Britain’s worst mass shooting by opening fire at a primary school.
It can now be revealed that Prosper had a sick desire to carry out Britain’s worst mass shooting by opening fire at a primary school.
The teen wanted to achieve “lasting notoriety” and to “imitate and even surpass” other mass killers around the world.
Prosecutor Timothy Cray KC said: “He understood his plans, if realised, would bring about the greatest number of deaths in a school or other mass shooting in the United Kingdom and possibly even in the United States of America.”
Prosper had written a chilling note that told how this would be “one of the biggest events ever”.
He had also scrawled “kill all” on a diagram that showed the early years classroom at St Joseph’s.
The court was told he was “not just play acting or fantasising” and that the murder of his family was “killing for the sake of killing”.
He managed to get his hands on the deadly weapon by creating a fake firearms licence and offered a gun enthusiast £600 for a shotgun and cartridges – £150 more than the asking price.
Prosecutors believe he planned to massacre kids as young as four at St Joseph’s Primary School then take his own life.
The plot was foiled by police, who had seen him acting suspiciously after shooting dead his family.
Officers discovered a loaded shotgun discovered in bushes nearby alongside more than 30 cartridges – one for each child Prosper planned to kill.
Prosper could be heard in police bodycam footage whinging “it’s not murder” repeatedly as he was arrested.
Police had swarmed the home at around 5.30am after neighbours heard “loud bangs” that sounded like shots being fired.
Officers discovered Juliana and two of her four children dead inside the flat, having all been shot in the head.
Kyle had also been stabbed more than 100 times, while Giselle was found under a table as though she had been “trying to hide”.
He fired seven shots in total – the first being a test shot on a teddy bear in his bedroom – meaning he would have stopped to reload twice.
Prosper’s chilling internet searches
THE court was told Prosper was “continuously” on his phone between midnight and 4am on the morning of the triple murder.
He searched for “shotgun injuries to the neck” as well as other sadistic terms.
These included:
- What will happen on 13th September?
- Do you die if shot in the neck?
- Does sex with a corpse feel good
- Man shoots woman in the head at close range
- Woman raped and killed
- How lethal are neck gunshots
Prosper also searched for the murder of Sarah Everard.
Officers found blood splattered throughout the flat, with Kyle shot and stabbed in the kitchen.
His sister was discovered in the living room of the property and mum Juliana was in the hallway.
The court heard Prosper originally planned to kill his family in their sleep then remain in the flat with their bodies until the primary school had filled up with children.
But his murderous plan was interrupted when his loved ones “realised something was terribly wrong and challenged him”.
This led to an “extended, violent struggle”, the prosecutor said.
Prosper later told the medical practitioner that he wanted to shoot and rape Giselle, but his mum “messed it up” by waking up.
Following his arrest, Prosper made a string of disturbing comments in cell, including: “Are you capable of what I have done?”
He also said: “There was no choice, I had to do it.”
After the horror, it emerged Prosper had a chilling internet history.
He had shared a number of vile videos leading up to the killings on social media where he defended paedophiles and necrophilia.
Prosper also poured over previous school shootings – including the 1999 Columbine High School massacre.
At the time, he was showing a “deep alienation from normal life and interest in the darkest sides of humanity”.
The court heard Prosper had undiagnosed autism spectrum disorder (ASD), but displayed “extreme lack of empathy with others and an extreme lack of remorse” that cannot be explained by ASD alone.

Nicholas Prosper imitated firing a gun before shooting dead his family[/caption]
Prosper used a plank of wood to skulk around the family home[/caption]
He then uttered ‘bang’ while pretending to shoot through a door[/caption]
He accessed one site that showed videos of people’s final moments before they died but was banned after making pro-paedo comments.
In the months leading up to the triple murder, Prosper imitated firing a gun at the family home where he killed his family.
He had filmed himself in the kitchen of the flat prowling around in a bright yellow bucket hat and jacket.
Smirking at the camera, the teen menacingly held up a piece of wood to imitate a large gun as he pretended to fire.
Prosper then pointed the “weapon” through an open door and said “bang” as though he was firing at someone not in the shot.
The warped teen also had an obsession with a child character called Clementine from The Walking Dead video game.
In one clip posted after the killings, he told the camera: “I am the chosen one; chosen by Clementine. I am guided as Christians are guided by Jesus Christ.”
He also threatened sister Giselle over her “incorrect choice” on the game.
Prosper said: “On June 30, my sister decided to make the incorrect choices on episode one of season one of The Walking Dead games, and for that her face will be mutilated further than necessary.”
Hours later, the monster fatally shot Giselle in the head along with his mum and brother.

Juliana was found at home in September[/caption]
Daughter Giselle, 13, was among the victims[/caption]
Son Kyle, 16, was also found dead[/caption]
Paying tribute to Kyle, Giselle and Juliana, their devastated family said: “Julie was a strong, loving mother to her four beautiful children, who were her absolute world.
“In her spare time, she was a keen athlete and enjoyed raising money for charity – she was always putting others first.
“Kyle was a kind and funny young man who loved football and boxing.
“He was creative and thriving on TikTok, a big talent with massive potential.
“Kyle’s friends were his everything.
“Giselle was a beautiful soul and caring young girl; she liked to laugh lots and loved her family and big brothers.
“She was so loveable with an infectious smile.
“She was also an exceptional pupil at school and was loved dearly by her friends in Year 9.”

Prosper was also planning a school shooting[/caption]
Police had been called to reports of welfare concerns[/caption]