Couzens was handed a whole life order, meaning he will die behind bars, after kidnapping, murdering and raping Sarah Everard in March.
He posed as an undercover policeman on a Covid patrol and showed her a warrant card in order to handcuff her and lure her into his car.
Speaking after the sentencing on Thursday Deputy Met Commissioner Sir Stephen House said: “We will not operate plain clothes officers on their own. If we do use them, they will be in pairs.”
He said there will be “occasions” where that is not possible – such as when a pair of officers are split up – and noted that off-duty officers not in uniform “put themselves on duty” when they come across an incident.
Sir Stephen House acknowledged that a warrant card may not be enough to convince all members of the public that the holder is a legitimate police officer.
He went on: “Producing a warrant card and saying ‘I’m a Metropolitan Police officer’ may not be enough in certain circumstances.
“We are instructing our officers, the policy going forward will be that they must facilitate a greater trust.
“If that is, if necessary, by allowing phone calls to be made to our control room, so that the officer can show the warrant card and the person in the control room can say ‘yes, Steve House is a police officer and his warrant number – which will be on the warrant card – is as follows’.
“That should be enough to confirm identity, we believe. We know we have to go further to achieve trust and to prove identity of plain clothed officers.
“And we are prepared and keen to do that.”
Metropolitan Police Commissioner Cressida Dick said she recognised the “brutal” murder of Ms Everard had damaged trust in the police.
She said: “This man has brought shame on the Met. Speaking frankly as an organisation, we have been rocked.”
Ms Dick also acknowledged that the murder had shaken trust in the police.
“I recognise that for some people, a precious bond of trust has been damaged,” she said.
“As Commissioner I will do everything in my power to ensure we learn any lessons.
“I know that what happened to Sarah, and what has happened to other women in London and beyond in recent times, has raised important questions about women’s safety.
“Here in the Met I commit to keep working with others to improve women’s safety and reduce the fear of violence.
“There are no words that can express the fury and overwhelming sadness that we all feel about what happened to Sarah. I am so sorry.”