Hannah Bonser Credit: ITV Yorkshire

A twenty six year old woman , with a history of mental health problems, has been found guilty of murdering a schoolgirl in a random attack .

Hannah Bonser, 26, stabbed teenage schoolgirl Casey Kearney once in the stomach with a kitchen knife in a random attack as the youngster walked through Doncaster's Elmfield Park on the way to a sleepover at a friend's home.

13-year-old Casey managed to phone for help and was taken to Doncaster Royal Infirmary where she died later from her injuries.

Sheffield Crown Court heard. Bonser's legal team claim she was a paranoid schizophrenic and was suffering from diminished responsibility at the time of the Valentines Day stabbing.

But Prosecutor Graham Reeds QC told the jury this was not a diagnosis accepted by other mental health experts who have examined Bonser over many years. Mr Reeds said it was the prosecution case that Bonser was suffering from a personality disorder and, at the time of the attack, this did not "substantially impair" her ability to understand what she was doing.

The jury was told about Bonser's psychiatric history and her previous attempts to get admitted to hospital. They also heard that Bonser had waged a long campaign to get rehoused from her Doncaster town centre flat which she told people was "possessed by demons."

David Fish QC, defending, told the jurors it did not make sense that Bonser would make up symptoms. He asked them to consider why she had never said the voices in her head had asked her to kill a girl - a statement which would support the diagnosis of schizophrenia.

The jury took just two hours to reach their verdict. Bonser was jailed for life and told she must serve a minimum of 22 years in prison.