A woman with a history of mental health problems has been found guilty of murdering 13-year-old Casey Kearney in a park.
Hannah Bonser, 26, stabbed the teenager in a random attack in Elmfield Park, Doncaster, South Yorkshire, on Valentine's Day.
A jury at Sheffield Crown Court rejected Bonser's claim that she was guilty only of manslaughter due to diminished responsibility.
The judge, Mr Justice Cranston, said he will pass sentence at 2pm.
Bonser showed no emotion when the jury foreman returned the guilty verdict after two hours of deliberation.
She sat in the dock looking ahead, as she has done throughout the week-long trial, surrounded by four prison officers.
There were cries of "Yes" from the public gallery which was packed with Casey's family.
Her father, Anthony Kerney, appeared to wipe away tears.
Many in the gallery were wearing orange ties and scarves - one of Casey's favourite colours - in memory of the teenager.
Casey Kearney was a happy, ordinary 13-year-old girl who was simply "in the wrong place at the wrong time."
The teenager did not know Hannah Bonser.
They probably did not even exchange any words when they encountered each other in Doncaster's Elmfield Park with such tragic consequences.
Casey was heading for a sleepover with her friend Lucia Franco when she was stabbed by Bonser on Valentine's Day.
Her mother, Kerry Day, has described how it had only been a couple of months since she had started letting her daughter use the bus to go into town to meet friends.
Casey caught the no 55 bus towards Doncaster town centre but missed the stop where she was planning to get off.
She still used the same park entrance after walking back from the next bus stop but who knows whether, if she had got off at the right stop, she would have missed Bonser altogether.
The jury in the trial heard Lucia describe how her friend's constant stream of BlackBerry Messenger (BBM) chatter stopped suddenly on her way to her house.
As one lawyer said in court: "She really, really was in the wrong place at the wrong time."
After Casey's death, Mrs Day and Mr Kearney paid tribute to their daughter and said: "She was the most beautiful, intelligent and bright young girl with her whole life ahead of her."
In the weeks which followed, the community of Rossington pulled together in memory of Casey.
More than 200 people took part in two charity walks and a concert to raise money for her family.
Britain's Got Talent finalists 2 Grand performed at a packed benefit gig.
Hundreds of people attended Casey's funeral in March, many wearing orange - one of her favourite colours.
A tribute was read from her father which said: "From the moment you were gone I knew life could never be the same again and the pain of losing you would be intense for a long time to come, probably forever.
"I am sure everyone will agree what a wonderful young girl you had become."
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.
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.
She did get a black belt in taekwondo.
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.