And it's not even the stores themselves: They were opened in neighborhoods with "broken windows", they didn't create them. Lots of stores are messy.

I have a few near me in my average suburban neighborhood and I've never heard of any shooting, and a search of local crime blotters and newspapers doesn't turn up anything either. In the entire state I found roughly 1 robber per year over the past few years. Convenience stores with many fewer locations get hit more than that, but I don't think they cause violent crime.