Regarding the dumpster: Install surveillance cameras. Some are reasonably priced that provide HD, night vision, and zoom in capability for facial and license plate recognition. Research before purchasing, not all cameras are created the same.

The business owner was the creator of this situation. Placing the open, unsecured, easy accessible dumpster is very tempting, not intended for public use, but is tempting. It 'appears' the dumpster is protruding into the right of way of the street. Should personal injury or property damage occur, the store owner could be held liable. Place the dumpster next to the entrance of the business. Before sun down, the business owner will secure and place the dumpster in an area less accessible and less visible to the public. Get rid of the crap and the flies will usually disappear after the (temptation) smell is gone. Be considerate of back door neighbors.