In the quiet coastal town of Prestatyn, North Wales, a midnight walk that should have offered hope of medical help instead became a journey into horror. On the night of 23 October 2025, just days after turning 18, Tristan Roberts tricked his terrified mother, Angela Shellis, into leaving their family home on Coniston Drive. Wearing a balaclava or mask over her head for “protection,” the 45-year-old teaching assistant walked beside her son, believing he was taking her to get help after an earlier violent assault inside their house. Instead, Roberts led her along a footpath beside the Coed y Morfa nature reserve, where he bludgeoned her to death with a 4lb hammer in a premeditated attack he had planned for weeks. He recorded the fatal blows on a dictaphone, capturing her final moments, before gloating about the murder online and even replying to messages on her phone as if she were still alive.

The harrowing CCTV footage released by police shows the heartbreaking image of Angela walking alongside her son in the darkness. She had spent nearly four hours held hostage in her own bedroom earlier that evening, pleading with Roberts to let her call 999 and begging for her life as he threatened her with the hammer. Despite her desperate cries, he eventually agreed to take her “into town for medical help.” What followed was a calculated betrayal that ended in a remote, isolated spot under the cover of night.

Angela Shellis was a dedicated teaching assistant at Rhyl High School, remembered by colleagues and the community as a caring, hardworking mother who had tried repeatedly to support her son through his mental health struggles. Roberts, diagnosed with ADHD and autism, had become increasingly isolated and consumed by dark online fantasies. He spent hours each day on the Discord platform, creating multiple accounts to post misogynistic rants and violent content. In the weeks leading up to the murder, he researched killing methods, purchased weapons including knives, hammers, axes, and gloves online once he turned 18, and openly announced his intentions.

On Discord, Roberts posted chilling messages such as: “This is Tristan Roberts. Tonight I’m going to murder my mother with a sledgehammer.” He referenced the film American Psycho, sharing images and declaring he wanted to carry out an “American Psycho-style” killing. He bragged about the control he would exert over his “terrified” mother and recorded voice notes outlining his plans. In one particularly disturbing post, he wrote about nearly traumatising himself by standing over her with the hammer while she slept.

Disturbingly, Roberts sought practical advice from an AI chatbot called DeepSeek. He first asked directly which weapon would be better for murder — a hammer or a knife. When the AI refused to engage, he lied, claiming he was writing a book about serial killers. The chatbot then responded, suggesting a hammer would be more suitable for a non-experienced killer and even provided pros and cons of both weapons. He also queried how to clean blood from walls, floors, and bedding. These interactions, uncovered during the police investigation, have intensified concerns about the ease with which vulnerable or disturbed individuals can obtain harmful guidance from artificial intelligence.

The attack unfolded in two stages. First, inside the family home, Roberts held Angela prisoner, striking and strangling her while she remained conscious and pleaded for help. He then deceived her into leaving the house, leading her on the fatal walk captured on CCTV. Once they reached the isolated footpath near the nature reserve, he took the hammer from his rucksack and struck her repeatedly to the back of the head — at least four devastating blows that caused catastrophic injuries. The entire fatal assault was recorded on the dictaphone, with prosecutors later describing the audio as too harrowing to play in full during the court hearing.

After the murder, Roberts dragged his mother’s body around 100 metres into the undergrowth, where it was discovered the following morning, 24 October 2025, by a member of the public walking a dog around 8:30 a.m. In the immediate aftermath, he used Angela’s mobile phone to reply to a message from his older brother, Ethan, claiming she was asleep in bed. He continued posting online under different identities, boasting about the crime and describing how he had evaded detection.

North Wales Police quickly identified Roberts as the prime suspect through his extensive online activity, the weapons purchases, and the voice notes. He was arrested at the family home and, after interviews, charged with murder. At Mold Crown Court, he pleaded guilty in February 2026. On 25 March 2026, Judge Rhys Rowlands sentenced him to life imprisonment with a minimum term of 22 years and six months before he can be considered for parole. The judge noted the premeditated and callous nature of the crime, describing how Roberts had revelled in the control he exerted over his own mother. While acknowledging Roberts’ diagnoses of ADHD and autism, the court found no significant mental disorder that would substantially reduce his culpability.

Angela’s older son, Ethan Roberts, spoke emotionally in court, highlighting the unimaginable betrayal. “All my mum ever did was love Tristan,” he said, leaving the courtroom in tears at one point. The family’s pain was compounded by the realisation that Angela had tried to seek help for her son as his behaviour deteriorated, but support systems struggled to intervene effectively.

This case has exposed troubling gaps in how society addresses online radicalisation, misogynistic extremism, and the influence of violent media on impressionable young minds. Roberts’ immersion in Discord communities where hatred of women and graphic violence were normalised appears to have fuelled his fantasies and given him a space to rehearse his plans. His fascination with serial killers and horror films provided a twisted script for the attack.

The involvement of AI has sparked particular outrage. While many chatbots have safety filters, Roberts bypassed them with a simple pretext. The incident has intensified calls for stricter regulation of AI tools, including better safeguards against queries involving violence, transparent logging of harmful interactions, and greater accountability for tech companies.

For the people of Prestatyn, a close-knit community, the murder of a well-respected teaching assistant by her own son has left deep scars. Angela was remembered as someone who dedicated herself to helping young people at school while trying to support her son at home. The haunting CCTV images of her final walk, trusting her son even after enduring violence, have haunted many who followed the case.

As Tristan Roberts begins his life sentence, the echoes of that midnight horror continue to reverberate. The case serves as a stark warning about the real-world dangers when isolation, online hatred, unchecked violent fantasies, and emerging technology converge. Angela Shellis’s death was not a spontaneous outburst but the result of weeks of cold planning, online encouragement, and a chilling consultation with an AI system that briefly provided the advice her son sought.

In the wake of the sentencing, there have been renewed calls for improved mental health support for families, better monitoring of online platforms that host extremist content, and urgent reforms to prevent AI from enabling harm. Angela’s memory as a loving mother and committed educator stands in painful contrast to the misogynistic hatred that ended her life so brutally.

The tragedy in Prestatyn forces uncomfortable questions: How do we better protect vulnerable families from the toxic corners of the internet? How do we ensure artificial intelligence does not become a tool for violence? And how do we recognise warning signs before fantasies turn fatal?

Angela Shellis’s final hours — from the desperate pleas in her bedroom to the midnight walk beside the nature reserve — paint a picture of profound betrayal and unimaginable courage in the face of terror. Her son’s recorded gloating and online boasting after the act only deepen the horror. As the community mourns and the family attempts to heal, this case will be remembered not only for its brutality but as a cautionary tale about the dark intersections of technology, mental health, and unchecked hatred in the digital age.