Teenage killer planned 'massacre of the century'

A teenager who murdered three members of his family also planned to carry out one of "the biggest" massacres of the 21st century, it has emerged.

Nicholas Prosper used a shotgun to kill his mother Juliana Falcon, 48, his brother Kyle, 16, and 13-year-old sister Giselle at their home in Luton on 13 September 2024.

The 19-year-old was arrested in the hours after the murders, but told police of his "Friday the 13th" plan to kill 30 pupils at St Joseph's Catholic Primary School in an attack more deadly than the Sandy Hook shootings in America in 2012.

Prosper, who had admitted three counts of murder at Luton Crown Court, said his plot was interrupted by his mother who woke up before he could kill her and his siblings in their sleep.

A sentencing hearing - due to conclude on Wednesday - heard Prosper designed a distinctive black and yellow uniform for the killings which he scheduled for Friday the 13th so it had "a good name on it".

His plan would have seen him kill 34 people in total; his family, followed by four-year-old children at his old school, two teachers and then, finally, himself.

But after a noisy struggle with his family, his neighbours alerted the police, meaning Prosper had to leave his home hours ahead of his schedule.

After killing his mother and two siblings, he uploaded a video to YouTube, recorded the day before, where he suggested he planned to shoot his younger sister in the face.

Prosper flagged down a police car on nearby Bramingham Road after trying to hide the gun in some bushes, giving up on his deadly plans.

"The evidence suggests that what drove him on most was the desire to be famous or infamous," Luton Crown Court was told.

Police had been called to the Leabank building in the Marsh Farm area of Luton to reports of gunshots at 05:30 BST on 13 September.

Officers arrived at 05:50 and forced entry into the flat where they found the bodies of Prosper's three family members.

His younger sister, Giselle, was found underneath a dining table in the living room, looking "as if she had been trying to hide".

Kyle Prosper's death was particularly "shocking" as he had sustained more than 100 knife wounds.

Prosecutor Timothy Cray KC said Prosper had deceived a private gun seller online using a forged shotgun licence to acquire his gun.

He paid £650 plus £30 petrol money to the man for the shotgun and 100 cartridges.

Prosper considered stabbing the seller and taking the gun but decided not to as it meant the man's wife would have witnessed it.

He admitted to purchasing or acquiring a shotgun without a certificate, possessing a firearm with intent to endanger life and possessing an article with a blade or point.

Former teachers described Prosper as a "geeky" boy who was into computers.

By February 2023, there were concerns about his mental health and in March that year, he dropped out of school and his A-level studies.

"Whilst unemployed his life seemed to revolve around going to the gym and spending time alone on his computers," Mr Cray said.

Forensic psychiatrist Dr Iain Kooyman concluded the defendant showed all the symptoms of Autism Spectrum Disorder (ASD) but was undiagnosed.

He found Prosper had an "extreme lack" of empathy and remorse - something that could not be explained by ASD alone.

Prosper's internet history showed he had researched mass shootings around the world.

The defendant had started planning, or at least thinking about, the killings as early as Autumn 2023.

He searched for reports on the Manchester bombing, psychosexual stages and "why do people plead not guilty when it's obvious".

In the hours before killing his family Prosper researched shotgun wounds, necrophilia and the weather on the day of the attack.

After his arrest he told a medical practitioner he was going to kill his mother then brother before shooting and raping his sister but Juliana Falcon had "messed it up" by waking up.

In a typed plan of the attack he described it as "one of the biggest events ever."

In his YouTube video he referred to The Walking Dead video game but Mr Cray said Prosper was not "solely or even mainly motivated" by the that, due to his research of mass killers.

In a hand written note he said he had wanted time to "cannibalise my family, and rape a woman at knife point before the shooting".

"Why?" Because I could," he concluded.

The prosecutor added: "His stated purpose was to achieve national and international notoriety as one of the largest single incident murderers in criminal history."

Prosper, who wore a grey T-shirt, attended his hearing wearing black rimmed glasses.

He was visibly uncomfortable at times during the hearing, holding his head in his hands and covering his ears as evidence was read out

The court was told Prosper's parents separated when he was nine years old and the relationship he has with his father was "strained".

A statement written by Ray Prosper, his father and former husband of Juliana Falcon, was read out on his behalf by Mr Kray.

He said: "The pain of our loss will never be healed, this includes my whole family. Our lives will never be the same.

"When I heard the horrendous news that day, part of my soul died too. This is a lose-lose situation for us all and we have lost four family members."

His defence, David Bentley KC, told the court Prosper had "retreated into a harmful, internet world" and was "isolated from the real world".

He argued Prosper was living with an undiagnosed neurological development disorder in ASD, lacked any previous convictions and stressed his young age must be taken into account.

Judge Mrs Justice Cheema-Grubb adjourned the hearing until Wednesday when she is due to pass sentence.