A teenager who lured his mother to a park before recording himself beating her to death in a horrifying four-hour attack has been sentenced to life imprisonment.

Tristan Roberts, 18, from Prestatyn in North Wales, had openly discussed killing his “terrified” mother, Angela Shellis, 45, in online posts and voice recordings in the weeks leading up to the murder on 24 October last year.

Mold Crown Court heard that Roberts planned the killing for three weeks. On the night of the attack, he subjected his mother to a prolonged and brutal assault that began in her bedroom at around 11pm and continued until 3.30am. A four-hour voice recording captured the entire ordeal, including the moment he first attacked her, inflicting bruising to her face and strangulation injuries while she was held prisoner in her own room as he brandished a hammer. The recording was described as so disturbing that the judge ruled it should not be played in court.

Roberts convinced his mother to leave the house by pretending he would take her to a local pub to have her injuries treated. Instead, he led her to a nearby nature reserve where he killed her with at least four heavy blows to the head from a sledgehammer.

The teenager, who spent hours every day on the gaming platform Discord, later logged on and boasted about the murder. He had recorded the attack as a “trophy” and, in one chilling voice note made on the day of the killing, announced: “This is Tristan Roberts. Tonight I’m going to be Alex and I’m going to murder my mother with a sledgehammer.” He also changed his online status to “Tonight’s the night.”

Prosecutors told the court that Roberts appeared to be role-playing. In earlier online posts he wrote: “TBH with you I think I nearly traumatised myself today by putting my shoes on at like midnight when she was sleeping and having the hammer in my hand,” and “She’s going to vanish off the earth. I’ve tried everything else. Now it’s time.”

After delivering the fatal blows, he was recorded saying: “Oh God that was terrifying… That felt so crazy.”

The court heard that Roberts had bought knives, axes and hammers just 10 days after turning 18 — the legal age at which such purchases become permitted. In the weeks before the murder he had posted disturbing content openly discussing killing his mother and had recorded his thoughts on a dictaphone. He even consulted the AI platform DeepSeek, telling it he was writing a book and asking for the best way to kill someone; the AI reportedly suggested using a hammer rather than a knife. Roberts was also said to have a fascination with the US crime series Dexter and the horror film American Psycho. He harboured a particular hatred for “girls” and for his mother.

Angela Shellis, a mother-of-two who had recently suffered a knee injury and needed a crutch to walk, was found with multiple blunt-force injuries to the head in a seaside nature reserve in Prestatyn. A trail of blood led along a gravel path. At the scene, police discovered her crutch, a pair of black gloves, and a bloodied black balaclava that Roberts had forced her to wear.

North Wales Police found the body at around 8.30am. It was not until 1pm, when a worried relative contacted officers after hearing reports of a woman’s body being discovered, that Angela was formally identified. Roberts was arrested at the family home later that day. He was described as calm and compliant, and asked officers: “Is the body you found my mother?”

During the search of the house, officers found Angela’s phone hidden under a suitcase in a wardrobe. Family members who had tried to contact her received replies that were later believed to have been sent by Roberts posing as his mother to avoid raising suspicion. He had also told his older brother, who was away at university, that their mum was asleep in bed.

Ring doorbell footage captured the mother and son leaving the house on foot at 3.19am. CCTV showed them walking over a railway crossing, with Roberts carrying a rucksack containing the murder weapon. He returned home alone at 5.35am and was later seen leaving the house again carrying a carrier bag believed to contain bleach to clean the crime scene.

Roberts had a previous conviction as a juvenile for possessing a bladed article and had been diagnosed with autism and ADHD. Police have submitted an application for a safeguarding review.

Sentencing Roberts to life imprisonment with a minimum term of 22 years and six months, Judge Rhys Rowlands described the killing as “a truly awful way to die.” He told the teenager: “Angela cared for and worried about you. She would have been in pain and terrified. She could be heard saying that you were hurting her and to call 999 and get help for her and let her go. You ignored her pleas and managed to leave the house on the pretext you would walk to town to get help and got her to wear a balaclava.”

In a heartfelt tribute, Angela’s family said: “She had so many amazing qualities, but one of the greatest was the way she devoted herself to her boys. She was a fantastic and fiercely supportive mum, the kind who never gave up, no matter how hard life became. She fought tirelessly for them, and her love for them was unbreakable, a source of strength that carried her and her boys through every challenge.

“Her kindness was genuine, her laughter infectious, and her presence brought warmth into every room. She had a way of making people feel seen, valued, and loved, and that is something rare and precious. Losing her has left a space that can never truly be filled. She will be missed every single day by so many people whose lives she touched.”