Here is that law:
843.20 Harassment of participant of neighborhood crime watch program prohibited; penalty; definitions.--2011 Florida Statutes - Chapter 843 OBSTRUCTING JUSTICE(1) It shall be a misdemeanor of the first degree, punishable as provided in s. 775.082 or s. 775.083, for any person to willfully harass, threaten, or intimidate an identifiable member of a neighborhood crime watch program while such member is engaged in, or traveling to or from, an organized neighborhood crime watch program activity or a member who is participating in an ongoing criminal investigation, as designated by a law enforcement officer.
(2) As used in this section, the term:
(a) "Harass" means to engage in a course of conduct directed at a specific person which causes substantial emotional distress in that person and serves no legitimate purpose.
(b) "Organized neighborhood crime watch program activity" means any prearranged event, meeting, or other scheduled activity, or neighborhood patrol, conducted by or at the direction of a neighborhood crime watch program or the program's authorized designee. History.--s. 2, ch. 2004-18.
If Zimmerman's account is true, Trayvon was in the process of committing felony battery.
Trayvon was probably not committing an infraction against 843.20, because Zimmerman was not engaged in the organized neighborhood watch, nor investigating pursuant to an ongoing investigation designated by a law enforcement officer.
But I doubt the shysters will be put off by these concepts. They are too busy pretending a man with a Spanish-speaking Peruvian mother is not a true Hispanic and that bashing someone's head against the sidewalk is not potentially lethal force.
Agree with both assertions. Some are saying Zimmerman had no rights because he wasn't "officially" on-duty, but I don't see how a concerned community RESIDENT would not be allowed to watch strangers hanging around their home turf.
Hopefully (if you believe Zimmerman) It can be demonstrated that he made no hostile moves before Martin attacked him. What has come out so far seems to tip things in Zimmerman's defense.