Could anyone have predicted that Hannah Bonser would walk into a park with two kitchen knives and fatally stab a 13-year-old girl she had never met before for no apparent reason?
Despite today's verdict, this question may not be answered for some time.
A multi-agency investigation into Bonser's contact with a range of services is under way but no date has been set for its publication.
What is known is that the 26-year-old has been known to the mental health
services in her home town of Doncaster since she was 16 and first came to the attention of social services when she was nine.
She has been sectioned at least three times, Sheffield Crown Court heard.
Bonser grew up with her brother Ben in a Mormon family where she was educated at home when she was young.
Her life changed when her 30st mother, Roberta, died when Bonser was nine. Her father, Ronald, did not look after the children properly and social services became involved.
Psychiatrists told the court that Bonser moved from foster home to foster home from the age of 12. At first this was with her brother but they were later separated. When Bonser was 15, her father died.
The court was told that, in Year 9, aged about 14, a school report appeared to show she was a good pupil, working hard and had no attitude problems.
But a year later she left without taking any GCSEs.
Her brother has said previously that his sister was traumatised by the death of their mother, who was "the light of our lives". He said: "After she had gone, we fell apart."
Bonser's first contact with psychiatric services came in February 2002 when she reported low mood and self-harm to community nurses. Five months later, on her 17th birthday, she went to A&E at Doncaster Royal
Infirmary complaining of hearing voices.
She was diagnosed with an emotionally unstable personality disorder and for the next six years she had contact with mental health professionals in the community and when she turned up at hospital.
Between 2008 and late 2011 this contact stopped.
Then, late last year, things got much worse.
Her friend, Hayley Spouse, described how Bonser's condition deteriorated last summer when she developed an interest in Druids, started talking to rocks and believed birds were people out to get her. Miss Spouse put some of this down to her friend's heavy cannabis use.
In September, Bonser turned up at a spiritualist bookshop in London and so worried its owner - pagan priestess Christina Oakley-Harrington - with her bizarre behaviour that social services were called. This led to her being sectioned at a London hospital.
Bonser was taken back to a mental hospital in Doncaster where she was detained but released after five days following a further diagnosis of a personality disorder.
She returned to her Doncaster flat but complained constantly about how she believed it was inhabited by demons and wanted to be rehoused.
In January, she tried to get admitted to hospital again.
Still apparently concerned about demons in her flat, she went to the charity
Rethink, which helps people with mental health problems find accommodation. Rethink housed her for a week in its Doncaster centre.
Before leaving, she said she wanted to be seen by a doctor, wanted some
anti-psychotic medication and added that she was "a complete psychopath".
In one assessment at Rethink, she said: "I used to read until I read Catch 22 and my mind exploded. I used to watch TV but the noise started to split my head apart."
In another assessment she was asked about previous charges or arrests. Bonser said she "was given a warning for carrying a kitchen knife around the street when feeling scared".
Three days before the attack on Casey, she told Miss Spouse she was going to stab her ex-boyfriend to death and was "going to get anyone else who crossed her".
On the day before the attack she went to ask about her accommodation and was issued with a personal alarm.
During Bonser's trial, the prosecution and the defence called experts who gave very different versions of her mental state.
The defence case was that she was a paranoid schizophrenic.
Consultant forensic psychiatrist Alexander Shubsachs talked the jury through dozens of pages of delusional ramblings Bonser had written. These were found by police in her flat and also written by her in prison after her arrest.
But prosecutors said no other expert had diagnosed her as schizophrenic. They said she has consistently been diagnosed as having a personality disorder and suggested she might have made up some of the symptoms of psychosis.
The prosecutors said it may never be known why Bonser stabbed Casey but asked jurors to consider whether her repeated efforts to be rehoused and her numerous attempts at getting admitted to hospital may be clues.