Social services leaders admitted they made serious errors after they allowed a convicted drug dealer to look after murder victim Toni-Ann Byfield.
Toni-Ann with the man she thought was her father, Bertram Byfield
The seven-year-old girl was shot dead alongside Bertram Byfield - a crack dealer who she thought was her father.
Although social workers had placed Toni-Ann with her great aunt, they were aware she was also visiting Mr Byfield in his London flat.
Birmingham City Council chiefs admitted there were serious failings in her care and said they had let the child down.
Toni-Ann, who had come to the UK from Jamaica in 2000, had been looking forward to starting junior school in Birmingham.
However, she was also spending time with Mr Byfield at his flat in Kensal Green, north-west London, because she believed he was her father.
In fact, DNA tests after their deaths showed he was not related.
Toni-Ann and Mr Byfield were killed after a man burst into the London flat and opened fire last September.
Although paramedics battled to save them, both died on the way to hospital.
An independent report into the case criticised agencies involved in Toni-Ann's care - after carrying out a review of the decisions made by officials.
At a press conference on Thursday, the council said it was not fully aware of Mr Byfield's background.
'No thorough assessment'
Peter Hay, in charge of the city's social services, said his workers should have known more about Mr Byfield.
"We didn't make a thorough assessment and were not aware of his full background or his other life - we just looked at him as a parent.
"Bertram Byfield was honest in his dealings with us and acted responsibly.
"But we were too narrow in our focus and did not assess all the risks.
"There were serious failings and we let her down."
Mr Hay, admitted that they had not informed social services in London that Toni-Ann was staying in the area and said the social workers involved in Toni-Ann's case were not doing the same jobs now.
The review criticised Birmingham City Council's Social Care and Health Directorate, the National Immigration Service, and the Child and Family Courts Advisory and Support Service (CAFCASS) for failing in their professionalism and practice.
Children's Minister Margaret Hodge said it is vital that the lessons are learned
from the "tragic death" of Toni-Ann.
She said the case appeared to share similarities with that of eight-year-old Victoria Climbie, who died in 2000 while in the care of her great-aunt and her
boyfriend, both of whom are now serving life for her murder.
Ms Hodge said: "People, quite rightly, expect more from their local social services. Failure
is not acceptable and it's vital that lessons are learnt and acted on in
The review - carried out by David Lambert, a former assistant chief inspector
at the Social Services Inspectorate - concluded that the failings highlighted
"the need for professionals to maintain a thoroughly watchful and diligent
stance in respect of their safeguarding obligations to the children and young
people in their charge".
Mr Byfield, known as Anthony Pinnock in Jamaica, had previously served a nine-year prison sentence and survived an attempted shooting in 2002.
Scotland Yard believe he was affiliated to a Jamaican drug cartel and may have been killed over a drug debt he had previously tried to collect.
Detective Chief Inspector Neil Basu, leading the inquiry, said: "Tony Byfield may have been a drug dealer but no-one deserved to die the way he did - we believe watching the girl he loved as his daughter shot in front of him."
He appealed for information from anyone who knew Byfield's movements in Jamaica or knew the gang he was involved with.
A reward of £20,000 has been offered for information leading to a prosecution.