A teenager who spent weeks meticulously planning his mother’s killing — researching methods of murder, researching how to avoid detection and purchasing an array of potential weapons — has been sentenced to life imprisonment with a minimum term of 22 years and six months.
Tristan Roberts was 18 years old when he killed Angela Shellis, 45, a teaching assistant, in the early hours of 24 October 2025. In the weeks before the killing, he had posted a still from the film American Psycho on the messaging platform Discord, alongside messages suggesting he was experiencing violent urges. On the day of the murder, he recorded a voice note stating his intention to kill his mother that night.
The attack began at the family home in Prestatyn, north Wales, where Roberts kept his mother confined to her room for approximately four hours, during which she sustained facial bruising and strangulation injuries. In the early hours of the morning he persuaded her to leave the house, telling her he would take her to get medical help. The two walked to a nearby nature reserve, where Roberts produced a hammer from a rucksack and struck her repeatedly on the head. He recorded both the attack at home and the killing in the nature reserve on a dictaphone. After returning to the house, he left again — police believe he was intending to go back to the scene with bleach to destroy evidence.
Shellis’s body was discovered in undergrowth the following morning. A blood trail stretching 100 metres led to it, with gloves, a balaclava and the victim’s crutch — which she required for a knee injury — found nearby. Doorbell footage showed the mother and son leaving their home at 3.19am.
When arrested, Roberts appeared calm and asked officers whether the body they had found was his mother. He answered “no comment” throughout nine police interviews conducted over four days.
Sentencing at Mold Crown Court, Judge Rhys Rowlands said Roberts appeared to have “revelled in the control” he exerted over his mother, describing it as “a truly awful way for someone to die,” made worse by the fact that her attacker was her own son — someone she had “both cared for and worried about” in the weeks before her death.
Shellis’s elder son Ethan said in a statement: “All my mum ever did was love Tristan.” Her sister Sarah Gunther described her as a mother who “never gave up, no matter how hard life became” and whose love for her children was “unbreakable.”
Andrew Slight of the Crown Prosecution Service said the level of planning involved had been “elaborate and calculated” and that Shellis’s final moments “must have been terrifying.”
