Police must increase their use of stop and search to help combat a rise in violent crime, a senior officer has said.
Sara Thornton, chair of the National Police Chiefs' Council, says that while the power may have been used too freely in the past, the "pendulum has now swung in the opposite direction".
Ms Thornton's intervention comes amid concern about violent crime in London.
The Metropolitan Police has opened 55 murder investigations this year. Among these is the investigation into the death of teenager Tanesha Melbourne-Blake, 17, who was killed in Tottenham on Monday.
There were six non-fatal stabbings in the capital from Thursday night into Friday morning, and the number of suspected murders in March was higher than in New York.
Ms Thornton appears to have the support of London's mayor, Sadiq Khan, who told the BBC on Saturday morning that "stop-and-search based on suspicion of carrying an offensive weapon (is) going up".
There would be "more arrests as a consequence of this intelligence-led stop-and-search", he said.
Writing in The Daily Telegraph, Ms Thornton says concern is not restricted to London. Knife crime has "increased by 21% and gun crime by 20% on the previous year across the country", she said.
Nevertheless, chief constables tell her that officers are "hesitant" about using stop and search.
Numbers have fallen, she says, from nearly three quarters in the last six years from 1.2m in 2010-11, to just over 300,000 in 2016-17.
But while someone can only be stopped if officers have "reasonable grounds to suspect that a prohibited article is being carried", Ms Thornton says officers can feel "overly cautious about using a power that has been subject to so much political debate".
It has been controversial because black people are more likely to be stopped.
Ms Thornton says it is essential that those stopped are treated with "dignity and respect" and that body-worn cameras will "increase the confidence of the pubic that powers are being used properly".
She also says the use of powers specifically aimed at gang violence, under which a senior officer can search anyone in a specific area, has been "discouraged".
In London, the use of stop and search has dropped from 1,429 instances in 2011-12 to 23 in 2016-17.
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Barry Mizen, whose son Jimmy was killed in southeast London in 2008, told Sky News that "if stop and search is the short-term answer to put a break on the amount of deaths and stabbings we are seeing then I think we all have to support that".
He added: "But let's make it a short-term response. In the longer term, let's look to build a stronger community spirit."