24 Hours in Police Custody: The hunt for 'truly evil' teenager Nicholas Prosper who killed his mother and siblings
He planned more deaths, including the 'biggest massacre of the century'
24 Hours in Police Custody returns this week with one of the most sickening investigations of recent times – that of Luton serial killer Nicholas Prosper. The teenager murdered his own mother and younger siblings, and planned many more sick acts.
The award-winning true crime documentary exclusively follows one of the largest murder enquiries ever conducted by Bedfordshire Police.
On Sunday (October 05, 2025), Channel 4 viewers can tune in to the first feature length episode of a two-part special entitled Murder Is No Game. Here’s everything you need to know about the “appalling” crimes of Luton serial killer Nichola Prosper.
Luton killer Nicholas Prosper in police questioning on 24 Hours in Police Custody [Credit: Channel 4]
24 Hours in Police Custody: Murder Is No Game
Channel 4’s documentary 24 Hours in Police Custody is arguably one of the best shows on TV full stop, and the latest two-parter – Murder Is No Game – is no exception.
The first episode follows Bedfordshire Police as they receive a disturbing 999 call from a block of flats. Neighbours have heard gunshots in the early hours of Friday, September 13, 2024. Bedfordshire Police immediately scramble all available resources to the scene…
Tragically, it becomes clear that the gunman had killed several people in on of the flats. To gain access, armed officers fired smoke grenades into the flat in case the shooter was still inside. Police entered the premises, which was covered in blood. There, they found three members of the same family fatally wounded. They also found the spent shotgun cartridges.
However, one person was missing. There was no trace of the fourth member of the family and no sign of the gun. Police subsequently declared a critical incident. With an armed shooter at large, detectives from the Major Crime Unit began their murder investigation…
Who is Luton killer Nicholas Prosper?
Nicholas Prosper lived with his mum, brother and sister at their flat in the Leabank tower block – off Wauluds Bank Drive – in Luton. He was 18 at the time his family were shot dead. And police soon began to realise he was their prime suspect, and begin to probe his motivations.
Police finally arrested the teenager after a tense manhunt. Although he claimed he hadn’t murdered his mother, brother and sister, his actions were immediately alarming. On arrest, he repeatedly asked the police officers: “Are the schools in lockdown?”
Detectives realised their worst fears were true. Luton killer Nicholas Prosper HAD killed his family. But that was only the first stage in his plan. He wanted to gain notoriety by becoming the most deadly mass school shooter in history… He’d planned the “biggest massacre of the century” and picked Friday 13th especially.
Nicholas Prosper had plotted to kill pupils at his old school, St Joseph’s Catholic Primary, on Gardenia Avenue after murdering the three members of his family. Bedfordshire Police subsequently discovered that the 18-year old had meticulously planned all the murders by illegally obtaining a shotgun by faking a firearms certificate. Their analysis of his online activity also revealed something even more devastating…
Luton killer Nicholas Prosper’s motive: Teenager ‘craved notoriety’
Forensic analysis of Nicholas Prosper’s life online demonstrated that he craved notoriety. Described by those who knew him as “quiet” and “geeky”, he wanted to become the most deadly mass school shooter in history.
Nicholas had based his plans on other infamous school shooters. He had spend at least a year reading up online on the devastating massacres.
Bedfordshire Police also discovered that he’d modelled his killing spree on violent video games that allowed players to insert real school shootings into their play. While he was playing online, he’d become obsessed with a character from his favourite game. As a result, he had self-radicalised – and the line between fantasy and real life became blurred, with fatal consequences.
Police called his crimes “truly evil”.
Who were his victims? Who did he kill?
Nicholas Prosper killed his Buenos Aires-born mother Juliana Falcon, 48, his sister Giselle, 13, and his brother Kyle, 16. He used a gun and knife to kill his family in the early hours of September 13, 2024.
The Luton killer had placed copy of the novel How to Kill Your Family on mum Juliana’s body. He had also stabbed his own younger brother Kyle more than 100 times.
He also planned a mass shooting of at least 30 people at his former primary school. However, after a neighbour heard gunshots in the Luton flat, the police were called. This forced Nicholas Prosper to hide and stopped him from completing his sick mission.
Nicholas had wanted to kill 34 people including himself to achieve a higher death toll than the Virginia Tech shooting.
During the trial, prosecutor Tom Little KC told the hearing at the Court of Appeal: “What the facts reveal is a case which, on any view, was exceptional, even in the context of a murder.
“It was a murder of three people, two of them were children, including the intended rape of the sister. That did not take place, but it had been intended.”
Victims Giselle Prosper, 13, Juliana Prosper, 48, and 16-year-old Kyle Prosper [Credit: Bedfordshire Police/C4]
How did police catch him?
The teenage killer hid for nearly two and a half hours after murdering his family. Despite originally heading to the school to commit a massacre, he realised it was too early for the building to be open. After that, he gave up on his plans to commit a massacre at the school, and gave himself up.
Nicholas left his hiding spot and walked down Bramingham Road towards a passing police car. He flagged it down, and subsequently surrendered. He believed local schools would be in lockdown after the shooting and he would not be able to complete his plan.
Police found indecent images of children on his phone.
Luton killer Nicholas Prosper is a “truly evil individual”
Talking about the teenage killer, Detective Chief Inspector 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.”
She continued: “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. I have been utterly shocked and appalled by the actions and plans of the offender in this case. I am pleased that this truly evil individual will now be serving a significant proportion of his life behind bars.”
Police arresting Nicholas Prosper [Credit: Channel 4]
Bedfordshire Police ‘utterly shocked and appalled by the sickening actions of this individual’
Meanwhile Assistant Chief Constable John Murphy said: “Everyone at Bedfordshire Police is utterly shocked and appalled by the sickening actions of this individual. We are pleased he is now facing a significant time in jail.
“This was a lone individual whose plans were fortunately disrupted. I would like to pay tribute to the bravery of his family, the neighbour who called police, our officers who apprehended him, and all who have worked tirelessly to secure the compelling evidence which ensured he was brought to justice.”
He added: “I know this does not take away from the sheer horror of the incident and his sickening plans to target school children. I do not underestimate the impact on the staff, parents and carers of pupils at schools across the country, but particularly those associated with St Joseph’s School.”
Forensic psychiatrist Dr Iain Kooyman believed Nicholas showed “all the symptoms of Autism Spectrum Disorder (ASD)” but was undiagnosed.
He also found the killer had an “extreme lack” of empathy and remorse – something that could not be explained by ASD alone.
Where is Luton serial killer Nicholas Prosper now?
In February 2025, Nicholas Prosper appeared at Luton Crown Court. He pled guilty to three counts of murder, one count of purchasing a firearm without a firearm certificate, one count of possessing a firearm with intent to endanger life, and one count of having an article with a blade.
He subsequently received three life sentences for killing three members of his family. A judge sentenced Nicholas Prosper to life, giving him a 49-year minimum term in jail. The fact that he pled guilty and had not carried out the mass school shooting meant he was not handed a whole-life order. The judge also considered his young age.
The Attorney General’s Office said that Prosper “ought to have been given a whole-life order” which would prevent him from ever being released. The solicitor general subsequently referred the case to the appeal court under the Unduly Lenient Sentences scheme. They asked for a whole-life order to be imposed.
The Court of Appeal has rejected a request for a teenager who murdered three members of his family to never be released from prison.
‘No sentence can ever reflect the value of lives lost’
In July 2025, The Court of Appeal rejected a request for the teenager to never be released from prison. Lady Chief Justice Baroness Carr rejected the request. She argued that the killer’s young age meant he would be in his late-60s before he could be considered for release.
So Nicholas Prosper could be free one day. But it will be the mid-2070s before he is considered for release on parole.
Lady Chief Justice Baroness Carr told the appeal court: “Appalling though these crimes were, we are not persuaded that anything less than a whole-life order was unduly lenient. It is a sentence that requires a youth of 18, as he was at the time of his arrest, to remain in custody until he is in his late 60s and one that might result in him never being released.”
She went on to say: “No sentence can ever reflect the value of lives lost.”
Nicholas Prosper is now 19, and in HMP Belmarsh prison.
Who is Nicholas Prosper’s dad?
Although he didn’t live with him, Nicholas Prosper’s dad Ray Prosper was at the trial. The court was told that Nicholas’ parents had separated when he was nine years old. The relationship he had with his father was “strained”.
When court officials led Nicholas out of his first court appearance (on 16 September 2024), his father was there to support him.
In tears, he shouted at his son: “I still love you, son. It’s not your fault, OK?”
A statement written by Ray Prosper was read out on his behalf by prosecutor Timothy Cray KC. 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.”
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