Scotland Yard has hit back at criticism of the way it dealt with a killer who was left free to murder a grandmother in the street.
The force came under fire on Monday for failing to carry out a Police National Computer (PNC) check on Nicola Edgington, who called 999 five times to warn police that she might hurt someone before committing the murder.
Edgington, 32, was jailed for life with a minimum term of 37 years for murdering grandmother Sally Hodkin, 58, and trying to kill 22-year-old artist Kerry Clark.
Police watchdog the Independent Police Complaints Commission (IPCC) said the computer check would have revealed that Edgington had a violent history and had killed her mother six years before.
Commissioner Sarah Green said: "It is of great concern that no PNC check was carried out which would have immediately alerted them to Edgington's violent history." But Commander Neil Basu from the Metropolitan Police said the check would not have stopped Edgington.
Hours before the murder, she was taken to the Queen Elizabeth Hospital in Woolwich, south-east London, by police after staff at a cab firm became alarmed at her behaviour in the middle of the night. While waiting to be admitted, she rang 999 five times and warned that she was dangerous and would harm somebody if she was not sectioned. After a delay, she was taken to the mental health unit, Oxleas House, but walked out soon afterwards.
Commander Neil Basu from the Metropolitan Police said the PNC check would not have stopped her. "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," he said.
"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."