Take a look at Sweden for an example of a country where poverty is more or less absent due to a wide social safety net while crime is on the rise. It is not poverty which causes gangs to go out and rob teenagers of their expensive branded jackets, iPhones and sneakers. Some turn to crime to get luxury items, some do it to dominate others (Denmark has created a specific category of 'dominance crime' for this phenomenon), some do it to gain street cred etc.