There is “some link” between falling police numbers and a rise in violent crime, Metropolitan Police chief Cressida Dick has said.
The commissioner was speaking a day after Prime Minister Theresa May said there was “no direct correlation”.
It comes after two 17-year-olds were killed in separate stabbings in London and Greater Manchester at the weekend.
Ms Dick told LBC Radio the deaths show “how big of a challenge this is” and that it is not a London-only issue.
Jodie Chesney was killed in an east London park as she played music with friends, while Yousef Ghaleb Makkie was stabbed to death in the village of Hale Barns, near Altrincham.
Meanwhile, six people have been arrested over a gang attack at a Lancashire sixth form college. A machete has now been found near Runshaw College in Leyland, following Monday’s incident.
In her radio interview, Ms Dick also agreed that middle class recreational drug users had “blood on their hands” over recent deaths, adding the drugs trade was a key driver behind street violence.
Former Home Office minister Vernon Coaker has said the government should treat knife crime with the same urgency as terrorism.
Home Secretary Sajid Javid has said he will meet police chiefs to look at ways to combat violence.
Speaking about policing numbers, Ms Dick said: “If you went back in history, you would see examples of when police officer numbers have gone down and crime has not necessarily risen at the same rate and in the same way.
“But I think that what we all agree on is that in the last few years police officer numbers have gone down a lot, there’s been a lot of other cuts in public services, there has been more demand for policing, and therefore there must be something and I have consistently said that.
“I agree that there is some link between violent crime on the streets obviously and police numbers, of course there is, and everybody would see that.”
Total knife offences in England and Wales
Offences involving a knife or sharp instrument
Her comments come after the prime minister provoked anger on Monday by saying there was “no direct correlation between certain crimes and police numbers”.
Senior police officers have called for a reverse to recent cuts in staffing levels.
Richard Cooke, the chairman of the West Midlands Police Federation, wrote in the Daily Telegraph: “How can they ignore what is obvious to most of us – that the violence is out of control partly because there are simply not enough bobbies on the beat?”
Labour leader Jeremy Corbyn said Mrs May “must start listening” to police chiefs over the impact of cutting 21,000 officers, adding: “You cannot keep people safe on the cheap.”
Former Met commissioner Lord Hogan-Howe has called for 20,000 officers to be recruited to bring forces in England and Wales back to their 2010 levels, and says ministers have to “get a grip on the crisis”.
Ms Dick is recruiting for 3,000 new officers after receiving an increase in funding. She welcomed a boost to police numbers in London – but said they were still below the levels they were in 2013-14.
Hospital admissions for knife assaults
Number of admissions for assault by a sharp object, England
On the issue of drug use, LBC’s Nick Ferrari asked Ms Dick: “Is it fair to say, commissioner, that some of these middle class dinner parties that send out for cocaine on the weekend or whatever it might be, they’ve actually got blood on their hands of some of the people who are dying on the streets?”
Ms Dick said: “I think anybody who is not seriously mentally ill, seriously addicted, who is seeking ‘recreational’ drugs, particularly class A drugs, yes, I think that is a good way to put it, I do.”
The drugs trade is considered to be one of the key drivers behind street violence – especially so-called county lines networks that target children and teenagers to work as couriers.
‘More weapons off streets’
She said that when she became commissioner, tackling violent crime on the streets was her top priority – and it remained so.
She said the force was not failing to tackle the issue and was “working incredibly hard”.
“We are taking more weapons off the streets, we are arresting more people, we are doing more disruptive activity, as well as record numbers in the last few years of stop and search,” she said.
Ms Dick also noted that the number of homicides in London had fallen, with 20 so far this year compared to 29 this time last year.
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