A former chief superintendant who now works with Camden and Islington NHS Foundation Trust says gangs and knife crime should be looked at through “the prism of vulnerability”.

In the 1990s Dal Babu took white and Muslim youngsters from rival gangs in Islington and Camden to Belfast, so they could learn about the consequences of sectarian conflict between Catholics and Protestants.

Mr Babu served the Met Police for three decades and is now a non executive director at the trust.

He wants to see more joint training programmes for police, NHS and local authority workers and teachers, so staff can spot signs of vulnerability, such as kids having a new social circle of older friends or wearing expensive gifts, early and intervene.

"We need to be looking at issues around gangs, knife crime and radicalisation through the prism of vulnerability," he said. "Essentially what we need is to understand how important vulnerability is and look for the signs of that. We need to be talking to children, listening to what they're saying, encouraging them to get involved in positive activities or part-time employment."

He says it's important to understand the impact "adverse character experiences", such as mental health problems, substance abuse or a period of homelessness can have on people.

"It's about making sure we understand how any of these experiences can have a detrimental impact on children's wellbeing," he added.

"Young people's brains aren't fully developed as they're growing up, there is suggestion you don't start having a fully developed brain until you're 24. I think young people make poor decisions and it's about making sure we have the infrastructure around them.

"When I think back to my time as a Sergeant in the boroughs [of Camden and Islington] there was a lot more youth clubs. How do you make sure you have resources in place [so that] young people feel safe going there? We seem to have the buildings but we don't have, necessarily, the people to deliver those services.

"Having worked as a Pc and a Sergeant and an inspector and chief inspector in the borough's, I think I've got understanding of local issues. Over the years I've met some amazing teachers, counsellors, police, NHS staff - it's about how you get together to deal with the problems."

Mayor of London Sadiq Khan set up a violence reduction unit last year as part of a public health approach to crime. This was modelled on successful crime reduction programmes in Glasgow and USA.