17-year-old brutally killed his sister after a wrestling move turned deadly—his shocking motive revealed.

A seemingly ordinary sibling playfight spiralled into a horrifying act of violence when 17-year-old Mali Bennett-Smith brutally murdered his older sister, Luka Bennett-Smith, in their family home. The chilling details of the attack, fuelled by years of resentment, emerged in Bristol Crown Court as the teenager confessed to stabbing his 19-year-old sister to death after trapping her in a headlock.

Luka had agreed to let her younger brother practise a wrestling move on her, unaware that his intentions had turned sinister. Instead of releasing her as promised, Bennett-Smith tightened his grip, choking her in a hold that quickly became deadly. Then, in an act of cold-blooded savagery, he took a knife and plunged it into her body, ending her life in an instant.

When questioned by authorities, the teenager displayed no remorse, admitting he had long harboured resentment towards Luka. His reasoning for the brutal murder was as callous as it was shocking—he found her “annoying.” His lack of regret left the court stunned, with prosecutors and family members struggling to comprehend the sheer senselessness of his crime.

The fatal attack took place in St Andrews, a quiet district now scarred by the chilling events that unfolded behind closed doors. Neighbours described the family as ordinary, making the revelation of such a brutal crime all the more disturbing.

During sentencing, the court heard how Bennett-Smith had planned the attack, using what should have been a harmless sibling interaction as a pretext for murder. The judge acknowledged the deep tragedy of the case, handing the teenager a minimum sentence of 10 years and five months in detention.

As the community reels from the shocking crime, many are left grappling with one haunting question—how could a teenage boy turn so violently against his own sister?