So was Trayvon Martin guilty?

Mr Zimmerman has been acquitted of the second degree murder of teenager Trayvon Martin.

The undisputed facts of the case appear to be thus

Mr Martin was on his way back from a shop
Mr Zimmerman saw Mr Martin
Mr Zimmerman chased Mr Martin
Mr Zimmerman killed Mr Martin

Mr Zimmerman claims he felt threatened by Mr Martin. That Mr Martin attacked him.

With Mr Martin lying dead, there is no witness to counter this story.

It seems that US law does not allow Mr Martin to use his fists to defend against an arms bearing, pursuing Mr Zimmerman, but does allow Mr Zimmerman to shoot and kill an otherwise innocent individual with whom a confrontation began only after Mr Zimmerman chased him.

Mr Zimmerman confirms he chased Mr Martin.

This does not seem like justice to me.

If Mr Zimmerman can reasonably shoot and kill Mr Martin because he felt threatened, could not any black teenager reasonably feel threatened in the presence of Mr Zimmerman?

Will the law protect their 'right' to shoot and kill in preemptive self defence?