This seems like an empirical question, not something to like or hate. Does poverty drive crime? Is reducing poverty effective in reducing crime? If yes, then I would say that is a good place for policies to focus.

I know more about Denmark (where I live) than Sweden, but here poor areas do seem to be by far the source of most crime, and that applies to both immigrants and non-immigrants who live there. The social problems in the different communities manifest somewhat differently, but both native & immigrant communities in the "bad" parts of Copenhagen have social problems. The biggest difference seems to just be that they join different gangs: ethnic Danes in areas with high degrees of social problems get involved in mainly-Danish biker gangs, while immigrants with social problems get involved in mainly-immigrant gangs. A large feature of Copenhagen crime in recent years has been the Danish and immigrant gangs fighting for control of the drug market. (Prior to that, the Danish gangs fought among themselves for it, so immigrants didn't start this particular problem: http://en.wikipedia.org/wiki/Great_Nordic_Biker_War)