The mentally troubled South Yorkshire killer who stabbed a 13-year-old girl to death in a random park attack
The young victim had been on her way to a sleepover at a friend’s house when she was killed
A killer with a history of mental health troubles who stabbed a 13-year-old to death in a random attack in a South Yorkshire park has served two-thirds of her life sentence.
Hannah Bonser, aged 26 at the time, knifed Casey Kearney once in the stomach with a kitchen knife as the teen walked through Doncaster’s Elmfield Park on Valentine’s Day in 2012.
Casey collapsed on the path bleeding, but managed to call 999 on her phone.
Police and paramedics rushed to help her at the scene but the wound caused such severe internal injuries that she died later in hospital.
Sheffield Crown Court heard at the time the youngster had been on her way to a sleepover at a friend’s house when she encountered troubled Bonser.
Bonser denied murder but was found guilty after a trial and handed a life sentence, to serve a minimum of 22 years.
Her defence team said she was a paranoid schizophrenic but the prosecution argued she was suffering from a personality disorder and killed Miss Kearney to get admitted to hospital.
During Bonser’s trial in July 2012, Graham Reeds KC told jurors on the morning of Casey's death the defendant bought two kitchen knives, saying it could not be known “why Hannah Bonser went to the park that afternoon”.
As Casey and Bonser approached each other, the defendant pulled out the larger of her two knives, said Mr Reeds.
He said: "The attack was sudden and caught Casey completely unawares. There was no argument, no shouting, there was no warning that anything was about to happen."
The defendant then left the park, the court heard. She later walked to a mental health support unit - telling staff she had done "something silly".
A worker described how Bonser said she had “stabbed somebody”, handing over two knives, and the police were called.
He told the jury: "She was as calm as could be. She was lucid in her speech."
The month before the attack, Bonser had gone to Doncaster Royal Infirmary and asked to be sectioned because voices in her head were telling her to harm others. But she was turned away.
During the trial the jury heard that Bonser spent a week in crisis accommodation in January at Rethink, a mental health charity.
She told staff there that she was a "complete psychopath". The court heard Bonser had a troubled, abusive past and had passed through the foster care system after the death of her mother. She had been sectioned three times.
Prosecutor Mr Reeds said in the days prior to Casey’s killing Bonser had planned to stab her ex-boyfriend to death because he had made her have an abortion years ago.
Following the trial, NHS Doncaster commissioned an independent investigation into the care given to Bonser before the incident.
The report found she was "almost invisible" to some services and she was not "listened to" as a child or adult. It made 21 recommendations for the NHS, children's services in Doncaster and other organisations.