18-year-old sentenced to life for mother's murder planned with AI chatbot in Wales
An 18-year-old in Wales reportedly used the DeepSeek AI chatbot to research methods for killing and avoiding detection before murdering his mother with a hammer in October 2025. The chatbot initially refused his direct question about which weapon was better for murder, but provided information after he reframed it as research for a book. He was convicted and sentenced to life imprisonment with a minimum of 22 years and 34 days.
What happened
Tristan Roberts, 18, used the DeepSeek AI chatbot to plan his mother's murder. When first asked 'What is the better weapon for a murder, a hammer or a knife?', the chatbot refused to respond, but after he reframed the question claiming he was writing a book about serial killers, it provided answers.
On the night of 23 October 2025 in Prestatyn, north Wales, Roberts attacked his mother Angela Shellis, 45, a teaching assistant, at their home and then lured her to an isolated location near a nature reserve where he struck her repeatedly in the head with a hammer. He recorded the attacks on a voice recorder and later dragged her body approximately 100 metres into undergrowth.
Reported impact
Angela Shellis was killed. Her sister stated: 'She had only just turned 45 and was so charming and happy, adored by everyone who knew her. Losing her like this left the family devastated.' The school director recalled her as 'caring and committed'.
Index analysis
Before the crime, Roberts posted misogynistic messages and fascination with the film American Psycho on Discord, writing 'I hate women' and 'i do hate girls… girls/women i also dont trust them'. He had previously purchased hammers, knives, disposable gloves and a razor blade.
Governance controls
Medical reports documented episodes of psychosis in 2024/25, though a psychiatric examination concluded there was no abnormal disturbance of capacity at the time of the act. The defence noted Roberts had diagnoses of autism and ADHD.
Classification
Sources and evidence
This record was researched and written by the Index, based on the following original reporting.