A question for those more legally knowledgeable than I.

Apparently Zimmerman’s lawyer is goint to use SYG as a defense.

Since SYG stipulates limits on the amount of investigation that can be conducted, it seems to me that the judge will have to decide at the outset of the trial whether SYG applies - otherwise all the evidence that the special prosecutor has collected (to base her determination to proceed with the case) could be inadmissible?

If the judge rules that the evidence is admissible, in other words says that SYG doesn’t apply, what does the defense do then?

And why would the defense use SYG when, obviously, the special prosecutor thinks that there was sufficient reason to investigate beyond Zimmerman’s claim of self defense?