The "for sure" part is that officers were chasing suspects on foot. One officer ended up at the fence line of a property.
Here's where accounts differ:
Owner of the dog claims there was one dog, his. He claims that his dog was not acting aggressively and was approaching the officer in a curious, but non threatening manner. He says that the officer stepped back over the fence, drew his weapon and shot the dog dead.
The police officer claims there were three dogs and the "fence" was very low. The dogs charged aggressively, the officer drew his weapon and shot one of the dogs, killing him.