Came from the reporter who was at the Walmart. Reporter says the shots came from a car driving by. Looks like police have looters cornered in the Office Depot (near the Walmart)
They are spread out in small looting groups.
Map of area - https://www.google.com/maps/search/walmart+ferguson+mo/@38.7469455,-90.2925465,13z/data=!3m1!4b1