The Met Police practice of posting photographs of seized knives on social media could be encouraging knife-carrying, according to a new study.
The University of Strathclyde research also found that sharing such images risked creating “a culture of fear” and “perpetuating negative stereotypes“.
London Assembly member Caroline Russell said the study findings meant Mayor Sadiq Khan needed to take action.
The Met Police shared more than 2,100 images of seized knives in 2020-21.
In October, Ms Russell presented these numbers to the mayor and asked him to intervene – a call she is repeating.
The mayor and the Met Police said they were still waiting for the outcome of other research due to be published next month.
The Met added that when “used appropriately”, images of knives “highlight the seriousness of the challenge” it faces.
By the end of last year a total of 27 teenagers had been killed in stabbings in London – the highest such death toll since 2008.
The University of Strathclyde study concluded that as well as potentially encouraging young people to carry weapons, the sharing of knife photos by police “may provoke negative reactions” and perpetuate “preconceived beliefs about who is likely to carry a knife”.
“How much more evidence do the police need?” Ms Russell said.
“Rather than tackling knife violence, we now know this practice is creating a culture of fear and perpetuating negative stereotypes which harm young people and the communities they live in,” she added.
Young people in London and knife harm charities support her request for Mr Khan to intervene, Ms Russell said.
“We now have academic evidence to back this call,” she added.
A spokesman for Mr Khan would not comment on the new research but said the mayor was awaiting findings from London’s Violence Reduction Unit.
A Met Police spokesman said the force was waiting for the same findings but welcomed the debate about its “number one priority” of tackling violence in all its forms. He added that “taking potentially lethal weapons off the streets is central to this mission”.
“We believe that, used appropriately, images of knives and similar weapons highlight the seriousness of the challenge and how we are tackling it,” the spokesman said.
“There are several ongoing academic studies examining the potential impact of the publication of these images.
“We are waiting for their findings before considering any change in our procedures.”
