In the United States, crime, especially by young people, can be correlated to the population density and type of housing that people live in.

If you want to live in a low crime area, you want to look for a suburban housing developement with 3 bedroom/2bath detached houses on (approx) 1/4 acres lots.

Apartment buildings with no place to play and areas of high population density breed hatred, frustration and violence. Perhaps this is a problem with the "estate" concept in England?

Also, families who own their own houses are less prone to producing violent kids, but I don't think that is as important as the type of housing or the population density.