Agencies missed opportunities to help a woman with a history of mental health problems who said she was going to harm someone before stabbing a 13-year-old girl to death.
Hannah Bonser was jailed for a minimum of 22 years after being found guilty of murdering Casey Kearney in Elmfield Park, Doncaster, South Yorkshire, on Valentine's Day.
Casey was going to a sleepover at a friend's house when Bonser - a total stranger with a diagnosed personality disorder and a history of cannabis abuse - stabbed her once with a 16cm kitchen knife she had bought earlier.
Bonser, 26, had been in contact with a number of agencies since 1993 when her GP raised concerns that she was being neglected by her parents, the independent report said. She was in touch with mental health services in Doncaster from 2002. In the months before Casey's murder, Bonser was admitted to hospital for a brief period before being discharged, and later went to hospital again after taking an overdose.
In January this year, she was offered crisis accommodation after she contacted mental health services and said she needed to be "locked up". She was sent home a short time later and discharged from treatment on January 30. On February 14, Bonser stabbed Casey as she walked through the park before going to a nearby mental health charity and handing over two knives as she confessed to what she had done.
The report, commissioned by primary healthcare trust NHS Doncaster, found events in Bonser's life could have been changed if agencies had not missed opportunities. It said she was "almost invisible" to some services, who often failed to listen to her concerns. But it made clear that Bonser's own actions led to Casey's murder.
"She told many agencies of her concern that she was going to harm someone. Assessments made by them did not identify a high level of risk of this occurring," the report stated. "There were missed opportunities to work with her more effectively. This could have changed the course of event's in (Bonser's) life and wellbeing."
The report made 21 recommendations to services including Doncaster Safeguarding Children's Board, Doncaster Children's Services, the Rethink Mental Illness charity, Rotherham Doncaster and South Humber NHS Foundation Trust, Yorkshire Ambulance Service, the Housing Options service and the M25 housing and support service.
Margaret Kitching, NHS Doncaster's nurse director, said everyone involved in the review would ensure that all the recommendations are fully implemented. She said: "Casey's death was a terrible tragedy and our hearts go out to her parents, family and friends as today will undoubtedly be another very difficult time for them."
Christine Bain, chief executive of Rotherham Doncaster and South Humber NHS Foundation Trust, said: "We accept all the findings and recommendations made following this investigation and we acknowledge that our service to Miss Bonser should have been much better. We have already taken action to improve our services to patients and service users and a detailed action plan is being implemented."