big question? Did the suspect know he was a cop when woke up?
Based on personal experience--they know you are a uniformed officer but they are used to you not doing anything. But, that only applies to people without weapons.
He was visiting his estranged wife. I would bet he was not in uniform.
I am surprised the article failed to state this, as it would seem to be the most important question.
In that area of San Diego, there are two types of officers: THe Quick and the Dead. If you are not the first, you will be the second. Information not in news: This guy[the perptrator] sat out in his car, taking on liquid courage. By his history, he was probably going to confront and shoot the "estranged " wife.