Britain's gang problem is in its "gestation" period and can be stopped before it takes a "multi-generational hold", US "supercop" Bill Bratton has said.
Mr Bratton, who is visiting Britain to share his experiences tackling gangs in New York and Los Angeles, said the issue would be easier to tackle in the UK because it does not span several generations.
Speaking after he delivered a lecture at the London School of Economics (LSE), Mr Bratton said: "It's easier to stop because you are not dealing with a multi-generational problem like we had in the United States where we had grandfathers and grandsons in the same gang."
He continued: "Latino gangs, particularly the Mexican gangs, first began in Los Angeles in the 1940s. The black gangs, the Crips and the Bloods that the gangs try to emulate by watching too much TV, watching The Wire and some of the other things out there, they began in the 1960s in my country."
Mr Bratton has met police chiefs in Manchester and London to discuss the issue of gangs, and will also visit Birmingham, before attending a conference on the subject on Thursday. He also spoke on the issue to MPs on the Commons Home Affairs Select Committee, and in his lecture echoed his views that you could not "arrest your way out of the problem".
Mr Bratton, who works as a security consultant, said "collaboration" was key to solving the problem, requiring police to work with Government at a local and national level.
After the lecture at LSE, entitled A More Secure World - From Neighbourhood to Globe, he said the gang situation in the UK was different to that faced by the US.
"The briefings I am getting is that up in Manchester their gang issue is about a generation old, when they first began to identify themselves as gangs and take up some of the structure and activities of US gangs.
"So before they take a multi-generational hold it's like weeding the garden, they are going to be easier to combat before they mature. So the importance of the effort that is being made at this juncture cannot be underestimated.
"In dealing with crime the idea is to prevent as much as you can so if you can find alternatives to prevent kids from getting into gangs you can prevent their growth but you can also focus on preventing their violence."