New Haven, Connecticut, has had a rash of robberies and shootings at convenience stores and service stations. So it is going to beef up police patrols at those stores? No. Offer firearms instruction to clerks? No. City officials have proposed forcing the stores to close at 11 p.m. and to open no earlier than 6 a.m. Officials say that will reduce the opportunities for robbery and violence. Store owners point out that 20 percent of their business comes during those hours, and the vast majority of customers don't rob or shoot anyone.