Commander Neil Basu has made a statement on behalf of the Metropolitan Police, following an IPCC report on the murder of Sally Hodkin by Nicola Edgington.
He said: "The death of Sally Hodkin is tragic and our thoughts go out to her family and to Kerry Clark who was injured by Nicola Edgington.
"Mrs Hodkin had been on her way to work in the early hours of Monday 10 October when she was approached by Nicola Edgington and stabbed in the neck. Edgington also assaulted Kerry Clark.
"Prior to this, Edgington was voluntarily taken by police to the A&E department of Queen Elizabeth Hospital, Woolwich and was waiting to be seen by a mental health team.
"The officers left her in a place of safety to be cared for by professionals trained to deal with people with mental health issues, and the IPCC investigation found that this was the correct course of action.
"Edgington made a number of calls to police from hospital asking for officers to attend whilst she was in the mental health assessment unit waiting to be assessed. She was reassured that she was in a place of safety and would be assessed by medical professionals.
"Police control room staff made contact with the hospital who advised that the hospital security had the matter in hand and that there was no need for police attendance.
"There has been criticism that officers did not conduct a Police National Computer (PNC) check on her details, which would have identified that Edgington had been violent in the past and had a previous conviction for manslaughter.
"With the benefit of hindsight this may have assisted officers with background information, however, as the IPCC investigation concluded, whilst Edgington was vulnerable, she was compliant and herself seeking medical assistance.
"The officers acted on the facts in front of them, which they do on a regular basis every day.
"A PNC check alone would not have prevented the actions that Edgington subsequently took.
"The IPCC concluded their investigation and no recommendations were made for either misconduct or learning for the MPS. They also identified that no police officer or staff breached the code of conduct or MPS policies.
"Despite this we will of course review the findings of the IPCC investigation.
"Once again our thoughts remain with the family of Sally Hodkin and with Kerry Clark."
More top news
Jeremy Corbyn has denied allegations of bullying saying "intimidation is not allowed" in the Labour party.
A woman remains in hospital after she was badly burnt by an electric shock in north London.
Police have released 12 images of people wanted in connection with what they describe as 'disorder' at a McDonalds in central London.