A 30 year research report was released 3 years ago here in Canada. The research was based on New York, Toronto, Mexico City and LA. The data indicated that neighbourhood violence increases when big businesses cause small "mom and pop" stores to shut down in favour of the Mega-Book/Video/Supermarket/Electronic/(Input store type here) store. The reasoning behind this was developed by an elderly Canadian Psychologist.
I will get the official book reference and post it here

Her research indicated that when small businesses exist in residential areas, more people are out and about. This increase in foot-traffic decreases the amount of criminal activity because of the fear of witnesses or availability of an easy target. Home break-ins increase dramatically when streets are empty. With big businesses such as Walmarts and Blockbusters, Circut Cities etc, people drive to their houses get out and go straight into their homes. The norm is to drive to highly commercial areas or shopping malls to get all of your necessities/entertainment/extras. Back in the day, one would walk down the street to get what one needed. Not so anymore. Not in major metros anyway. Hence, by shutting down these super stores, we can increase small businesses which would spread the wealth more, decrease poverty somewhat and decrease overall residential violence. This is not the cure but it is a good therapy to poverty and crime.