Leicestershire NHS Trust has apologised for its care of a mentally-ill woman who ran over and killed a mother and daughter in her car.
Gemma Montanaro, 41, said she thought Satan was driving when she lost control in Saffron Lane, Leicester, in 2007.
The previous evening she had been assessed in hospital by mental health teams and allowed to return home.
An independent report published on Wednesday found there had been a "lapse in safe standards of care".
'It was Satan'
Miss Montanaro's Vauxhall Astra mounted the pavement on 30 January, 2007 and hit a group of pedestrians.
Jane Malkin, 51, and her daughter Nicole Townshend, 24, were killed and a child was slightly injured.
A second child and a woman escaped unhurt.
Miss Montanaro was cleared of causing death by dangerous driving "by reason of insanity" but was banned from driving for life and given a court order under the Mental Health Act.
The court heard Miss Montanaro told police after the crash: "Somebody had their foot on my foot and their hand on my hand - it wasn't me driving, it was Satan."
On 29 January, 2007 she was assessed in the Leicester Royal Infirmary's accident and emergency department by a Deliberate Self Harm team and then a Crisis Resolution and Home Treatment team, who decided she was suitable for home treatment.
Care 'not adequate'
Wednesday's report found that although the tragedy could not have been predicted or prevented, she should not have been sent home from hospital without an adequate plan in place or an "interim care package".
The report made nine recommendations - eight for Leicestershire Partnership NHS Trust and one for NHS East Midlands which commissioned the report.
Antony Sheehan, chief executive of Leicestershire NHS Trust said: "The standard of care offered was not adequate, it was not up to standard, it was not what should have been expected by people using these services.
"The consequences were tragic and I want to offer a full apology for this to the families who have lost loved ones."