stip wrote:I think those standards should be higher too, but one battle at a time

I'm not convinced that there is a problem regarding 'civilian' shootings. If you have additional cases, I'd love to hear them, and on the face of it I don't know if this was a good shoot one way or the other.
If you are still upset at the Zimmerman verdict it might be because at the outset he was treated like something approaching law enforcent, with the exception of receiving pay.
I have a reasonable confidence that even with castle doctrines and stand your ground laws that juries will get it right most of the time.
However, when we give undue deference, such as when it involves agents of the state with statutory immunity then the repurcussions of taking another person's (or pet's) life become trivial.