It is bound to be true that a major influx of folk from other cultures will bring with it a percentage of criminal types that carry on as they would have in their own country. Not that we don't have our own sadistic bs. There have been incidents of major violence against folk before now. But I do suspect the rise if gun crime is probably a lot due to the attitudes of the bad guys who have been imported. Once you get one gang thinking it's ok, and not stamping it out immediately, then many gangs think it is the done thing.