The officer in question already had a string of abuse complaints being investigated.
The woman had called in about a case of sexual battery.
I have wondered if the shooter realized the perp they were called to find was likely an accomplice in earlier incidents who would likely roll over if caught. So he snapped.
All we can do is conjecture unless we get more information.
The officer in question had three complaints, one of which was resolved with no action against him, not three "abuse" complaints. The way people complain about cops you would be hard pressed to find an officer on any force without a complaint against him.
This is not a black/white issue or a Muslim/infidel issue. It's an issue of a cop who probably shouldn't have been a cop to begin with. Who panicked and who overreacted at a loud noise. But who will probably claim that he felt his life and/or the life of his partner was at risk so he defended himself and who will, unfortunately, likely get off because of it.