As usual... conflicting reports, and not enough information to say for sure what led up to the shooting.
But this, from the first link posted above by Double Naught Spy, seems to me to get at the crux of the matter: "...if Taylor was visibly displaying a weapon, the officer was expected to take action. He would, however, be expected to identify himself as an officer.
" (Emphasis mine.)
(from the Chicago Tribune) of an investigation into the handling of shootings by off-duty police indicates that in some places, at least, there's a double standard when it comes to off-duty officers who are involved in shootings, even when the context is a bar fight or a traffic dispute.
But if an off-duty police officer fails to identify himself, his actions ought
to be subject to the same "smell test" as those of any other citizen. If one of us, non-LEO types, pursued someone into his home, shot him, and then left the scene without calling 911, I think the consequences might be a bit more severe than being placed on desk duty pending an investigation.