Bad situation all the way around. If someone enters my house at night, dog probably wakes up first, goes to investigate. If I hear someone shoot my dog, I'm assuming its game on and will respond accordingly. If cops only identified themselves upon entry, I doubt I'd hear them in my bedroom, assuming they said it in normal voices and only once. Again, bad situation.

Side notes:

If you call 9-1-1 and can't give an address, try to hang around in a safe area and flag the cops to direct them properly.
Why does an unlocked door mean someone probably broke in?