"Stalked" is pretty aggressive language, and according to GZ, his initial suspicion was just related to him not knowing who this person was (he knew most of the residents) walking around at night, in the dark, in the rain, near the houses. I think that's a pretty reasonable case for someone to feel suspicious.
And to re-iterate, when prosecutors are trying to paint a portrait of childish innocence, I think it's perfectly acceptable to introduce evidence to the contrary. They're irrelevant if we don't try to elicit sympathy from the jury, but that's not how the prosecution handled things.
Prosecutor Richard Mantei argued that instructions for third-degree murder should be included on the premise that Zimmerman committed child abuse when he fatally shot 17-year-old Trayvon Martin because Martin was underage.
[1] http://tampa.cbslocal.com/2013/07/11/judge-rules-jury-can-co...
I don't know what media you saw when this case started, but Travyon was described as a young adult, not a young child. Further he was merely buying candy and going home when he was stalked by Zimmerman, doing nothing that should trigger suspicion or aggression.
> If prosecutors want to paint a personal portrait of someone for the sympathy of the jurors, stuff like this should absolutely be included by the defense.
The extra photos from the cell phone are entirely irrelevant to the facts of the case and they should not be presented to the court as though they were. The defense wanted to include those photos to paint a portrait of a scary black man to a group of white women in the jurors box.