The video of the house under construction showed Arbery go into the garage, then walking out. Then going around the house into the backyard and minutes later leaving through the front door, as if he had gained entry in the back of the house when he could not get in through the garage. At that point Arbery apparently realized someone was watching him from the trees in the yard across the street and started running.
Within minutes two police cars drove down the street, the second one a few minutes after the first one was driving at a very high rate of speed. It isn't difficult to figure that the first police car was in response to the first two 911 calls, and the second police car was responding after the confrontation with the McMichaels occurred.
Thanks!