Teenager Receives Life Sentence for AI-Assisted Mother Murder
A teenager who murdered his mother after seeking advice from artificial intelligence has been sentenced to life imprisonment with a minimum term of 22 years and six months. Tristan Roberts, aged 18, used a hammer to fatally assault his mother Angela Shellis, a 45-year-old teaching assistant, in what the judge described as a "truly awful" crime.
Chilling AI Queries Revealed in Court
Prosecutor Andrew Thomas KC revealed that in the weeks before the murder, Roberts had engaged with the AI search engine Deepseek, asking specific questions about committing the crime. He inquired about the best method to remove blood and other evidence from walls, floors, and bedding. When he asked whether a hammer or knife would be more effective for murder, the AI initially declined to answer but later responded when Roberts claimed he was writing a book about serial killers.
The AI suggested a hammer would be better for an inexperienced killer and provided detailed pros and cons for both weapons. This disturbing exchange formed part of the evidence presented at Mold Crown Court, where Roberts admitted guilt at an earlier hearing.
Recorded Attack and Online Activity
The court heard that Roberts recorded the horrific attack on a dictaphone, beginning the evening of October 23 when he announced his intention to kill his mother with a sledgehammer. The recording captured over two hours of conversation during which Ms Shellis pleaded with her son to release her and call emergency services.
After initially assaulting her with a hammer and strangling her at their home on Coniston Drive in Prestatyn, Roberts forced his mother to wear a balaclava and led her to Coed y Morfa nature reserve in the early hours of October 24. There, he delivered at least four heavy blows to her head with a lump hammer.
Following the murder, Roberts recorded himself saying, "Oh God that was terrifying... That felt so crazy," and later posted messages on Discord boasting about having "smashed her skull in so hard with a sledgehammer."
Disturbing Online Behavior and Mental Health Concerns
In the weeks leading up to the attack, Roberts had created multiple Discord accounts after being repeatedly blocked for discussing murderous thoughts. He preserved these messages as screenshots and created a profile with the username "Tonight's The Night" featuring an image of Dexter, the television serial killer character.
Digital notes discovered by investigators revealed Roberts cited "hatred of women" as a motive. The court heard that Ms Shellis had been increasingly concerned about her son's mental health, having contacted a social worker and friends on October 17 to report he had purchased a knife and hammer.
Ms Shellis had sought support for her son, who had been diagnosed with autism and ADHD. The attack occurred just ten days after Roberts's 18th birthday, with defense barrister David Elias KC suggesting declining mental health played a role in his actions, though it did not provide a legal defense.
Family Impact and Investigation
Ms Shellis's body was discovered by walkers later on October 24. Her elder son Ethan Roberts left the court in tears during the hearing, stating, "All my mum ever did was love Tristan." In an impact statement read to the court, Ms Shellis's sister Sarah Gunther expressed the family's complex emotions, including anger, confusion, heartbreak, and continued care for the defendant.
Detective Superintendent Andrew Gibson praised the bravery of Ms Shellis's family outside the court, noting that Angela had shown "tremendous bravery" during her ordeal and had continued to demonstrate her caring nature and love for her son despite the terrifying circumstances.
A family statement described Ms Shellis as a "fantastic and fiercely supportive mum" who "fought tirelessly" for her children. Denbighshire County Council confirmed the matter had been referred to the North Wales Safeguarding Board alongside partner organizations.
Judge Rhys Rowlands, delivering the life sentence, told Roberts: "You appear to have revelled in the control you exerted over your own mother. It was on any view a truly awful way for someone to die. It was made all the more dreadful by the fact her attacker was her own son, someone who it is clear she both cared for and, indeed, worried about in the weeks leading up to her death."
