Interesting situation.
It really highlights a lot of issues with how LEO are trained and then how they therefore behave.
When they finally find the place, they seem to be so frustrated with dispatch, the caller, trying to locate the residence, etc, that they then don't stop to consider how they're going to handle the next step. Or, this is exactly how they're trained to do it, in which case their training absolutely is going to create issues and escalate the situation. The first officer knocks on the door loudly, or at least what I think would have been herd very loudly from inside the apartment, and then I think rather halfheartedly shouts "Phoenix Police". It's hard to judge for sure based on audio levels, but given where the microphones are and that he was shouting at what sounds like a fairly sturdy door, I'm guessing the victim would have little likelihood of hearing that clearly, or maybe even much more than a muffled grunt. The shooter took up a position that would almost certainly prevent him from being seen via the peephole in the door, and would have left him largely concealed from somebody standing in the doorway until they step forward (since the door opens inwards). This position does make some sense, but had he been a little farther out from the wall he might have been identifiable. The other officer moved back and away from the door, again so that a view from a peephole would either obscure him or at least make it very hard to identify who he was. The next move was to turn on the 1000000W brodozer spotlight and shine it directly into the victims eyes, which means again no chance of telling immediately that these guys are actually uniformed officers. The timing of turning the light on is also of note, since he did not have it on until the door was opened enough to shine it in the victim's face/eyes, I would think if he just wanted the light on for the purpose of having light he would already have it on before then, instead he was intending for it to blind the victim. I believe that if the victim he had realized these guys were cops when he opened the door, he would not have stepped out, and likely this situation could have been easily deescalated. As is obvious from the video taken by the shooter, the victim didn't even know he was there until he was being shot (if then even). He also was complying as soon as he realized what they were (or at least that the one with the handheld laser was a LEO), and it was while he was complying (getting down and spreading his hands) that the shooter drew, and then proceeded to fire.
Their actions from then on out are another matter. Which again, is pointing at a lot of training issues, or maybe even an issue of how they operate.