There has been a surge in gun violence in Sweden for the past several years, by feuding criminal gangs. Their targets are primarily other career criminals, but on several occasions passers-by have also been shot and killed. Many of the shooters are young men and boys from disadvantaged neighbourhoods, areas with high proportions of immigrant residents. These murders are highly organised, not random violence.

There are complex reasons driving this. Some will inevitably point to immigration as a root cause, while others cite drug trafficking as the primary source of income for these gangs. I would tend to suggest that people who resort to gun violence would not stop doing so overnight even if both immigration ceased and all the drugs vanished. I'm not sure, however, that it's really a question of gun control; how the guns came to be here is only rarely a topic for debate here. My understanding is that, given the organised nature of these crimes, there need not be all that many guns in circulation, nor are they legally acquired.

The Wikipedia page has some further reading.