[Paul R.]

We don't know (I'm not even sure the LEO's are sure) if any officer was mortally wounded in the initial exchange of gunfire. But likely that'd not be more than one at most. (Recall that Reagan did not realize he was badly wounded, initially.)

From the press conference, IIRC it was the chief who said officers (plural) approached the downed suspect (Hughes) and then they took fire from the house.

Eventually a 17 y/o male and a woman (I'm not sure her age was given) in the house were detained. The big unknown at this point seems to be which of the two did the shooting from the house, or perhaps both did.

The motive(s) of the 2nd shooter(s) could be anything from "they ain't gonna get me" to "payback", or some combination.

If you are saying "Why weren't the LEO's vigilant about the house?", I don't know. A crime scene is never secure until the entire scene is secure...

[Fido969]

There is always the possibility some of the wounds were blue on blue. Once everyone unleashes, there are bullets flying all over the block.

[LuxAerterna]

We don't know...if any officer was mortally wounded in the initial exchange of gunfire

This is my hunch as well. As per their training, the LEOs would have been VERY careful in arresting this creep. This includes taking cover during the arrest, and being prepared to quickly return fire from the suspect himself.

It's taking fire from inside the house that caught them off guard. We'll see (eventually) how the investigation pans out.