A teenager who was planning a school massacre has been sentenced to a minimum of 49 years for the “horrific” shotgun murders of three members of his own family.

Nicholas Prosper murdered 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 on his way to his former primary school, where he planned to kill young children and teachers.

At Luton Crown Court, Mrs Justice Cheema-Grubb told Prosper: “Your ambition was notoriety, you wanted to be known posthumously as the world’s most famous school-shooter of the 21st Century.

“The lives of your own mother, and younger brother and sister were to be collateral damage on the way to fulfil your ambition.”

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.

Mrs Justice Cheema-Grubb paid tribute to Prosper’s family, whose noise as they were being killed alerted neighbours in their tower block in the Marsh Farm area of Luton.

She said: “Juliana Falcon, Kyle Prosper and Giselle Prosper’s deaths are almost certain to have saved the lives of many children.

“The community owes them its gratitude and their memory should be honoured.”

After the killing Prosper wrote a note, which read: “I was right in predicting no-one would’ve called the police had I killed them in their sleep.”

The judge told him: “You remain highly dangerous and it may be you will never be released.”

Warning: This story contains distressing details

Prosper had initially refused to attend court but was ordered to do so by the judge.

When he arrived he stared at the floor and did not stand while the judge passed sentence.

She told him: “I am conscious that nothing I can do or say can reflect the worth of Juliana, Kyle and Giselle’s precious lives or the depth of their shocking loss for their family and friends.

“You intended to unleash disaster on the community of Luton. Your plans were intelligent, calculating and selfish.

“Words such as heartless and brutal are insufficient to describe the horror of those last moments of the people who were closest to you.”

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

When officers forced entry to his flat they found the bodies of his family who had been shot. His brother had also sustained more than 100 knife wounds.

Prosper later 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 judge recounted: “After arrest you displayed no signs of agitation or mental distress. You were inappropriately cheerful and engaged the officers in conversation. You asked if the local schools were locked down.”

The 19-year-old pleaded guilty to three counts of murder and 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.

He was given a life sentence and told he will serve a minimum of 49 years.

He will serve 48 years and 177 days in prison once his time already served in remand had been deducted.

Following Prosper’s sentencing, Prime Minister Sir Keir Starmer’s spokesperson said: “This is the most appalling crime – we thank the police involved on the day who acted quickly to stop this vile perpetrator from carrying out the full extent of his awful plans.

“Our thoughts are with those who lost their lives and the wider community who were affected by this.

“The case has exposed some deep and longstanding weaknesses in the private sale of firearms and we are urgently looking at how we can tighten those controls.”

Mitigating, David Bentley KC argued Prosper was living with an undiagnosed neurological development disorder in autism spectrum disorder (ASD), lacked any previous convictions and stressed his young age must be taken into account.

The judge cited these as reasons for not issuing a whole life order, which would have meant Prosper could never leave prison.

She rejected the submission that the disruption to Prosper’s childhood caused by his parents separation when he was nine was a mitigating factor.

His father, Ray Prosper, sobbed as the judge recounted his son’s crimes and did not stop until after his son had left the court.

He had previously told the court how part of his soul died when he first heard the news.

Consultant forensic psychiatrist Dr Iain Kooyman said Prosper had traits of ASD.

The judge said this explained why Prosper became obsessed with subjects he was interested in, such as school shootings and serial killers, which he was researching in the hours before his murders.

Dr Kooyman also explained that ASD could be a reason why Prosper could not adapt his school massacre plan once it was interrupted.

However the judge noted ASD did not “impair your ability to understand the nature of your conduct, exercise self-control or form rational judgments when you decided to commit violent crimes”.

John Tizard, Bedfordshire’s Police and Crime Commissioner (PCC), said he has written to the home secretary to request an “urgent review” of legislation relating to firearms sales and exchange in light of Prosper’s crimes.

Tizard, who was elected as Labour PCC last May, wants Yvette Cooper to look at the law and “make us all safer”.

Det Ch Insp Sam Khanna said: “Our thoughts today are first and foremost with Juliana, Kyle and Giselle and all who knew and loved them.

“They should be who we remember, their names who we say, rather than the person who carried out these despicable murders and who intended to carry out an unimaginable level of harm to innocent school children.

“In my entire policing career, which has included many years spent investigating murders, I have never encountered anyone capable of such horrific acts whilst showing no remorse.”

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