Bill Sanders grew up in southern California, in the shadow of gang violence and drive-by shootings. He saw friends die and many more "get themselves maimed or paralysed".
He left ganglands behind when he studied at the University of California and Cambridge, and he is now mid-way through a PhD on the effects of "group juvenile delinquency" in Britain.
He said: "I use that term deliberately because gangs is a suspect term. Not all youth gangs are delinquent and not all gangs are criminal offenders. Most juvenile crime takes place alone or in pairs."
His supervisor at the London School of Economics is Dr David Downes, whose 1966 book The Delinquent Solution is still one of the most respected studies on gangs in Britain. Now Bill Sanders has pledged himself to an academic mission to change the perception of British youth gangs.
He said: "The majority of published research has come from the United States and as someone from such an environment, I know there is no comparison here to the vicious violence there.
"One thing that's struck me in my field research is how sweet the kids here often are. They are no vicious killers, often really nice kids who happen to live in the 'wrong area'. Many of them treat gang involvement as a passing phase. It could go when the acne goes."
However, he accepts the problem has escalated in Britain in recent years. He added: "Just because I'm saying it's not as bad as the US doesn't mean to say it's not bad by British standards. It is. And there is a great deal of public fear surrounding youth gangs. Clearly, the potential for violence and crime is increasing in the UK.
"A few years ago the majority of juvenile group crime was petty theft like shoplifting, nowadays the violent aspect is increasing.
"Many of those I've interviewed have a frightening knowledge of guns, who carries them and where to get one. When young people get used to knowing about and using weapons it opens up a whole big box of potential for new criminal possibilities. It wasn't long ago knives were unheard of in British classrooms. Now look."
The research aims to find out just how close we are getting to US patterns. What are the internal cultures, how much importance is attached to colours, dress codes and symbols, what are their beliefs, tastes, style?
The only way to get these answers was from the horse's mouth, so Bill Sanders interviewed up to 100 young people in Brixton, which he said he chose for its "notoriety" and because it is in the borough of Lambeth which has a high crime rate.
How has he been received on the streets of south-west London? "I guess my own background helps me to relate. The fact that I know what I'm talking about has helped me gain some credibility. I'm not from the police, the probation service or any other agency. I don't expect or want anything from them. I just care that these people aren't unfairly misunderstood."
As a foreign student he has no financial backing and is researching on a shoestring. "I don't need much as it's mostly field research, but some financial support would allow me to expand.
"The UK is at the stage where clear, qualified, up-to-date research into how to prevent a US gang scenario is urgently needed. It amazes me to think there has been massive media sensationalism on the subject, but so little in the way of solid sociological academic research - the type of research which informs and influences policy."