Two people do not have to be up close to exchange information. Zimmerman just wanted to know why Martin was in the apartment complex. Simple question with a simple answer.
Mr.Zimmerman has, as a member of community watch, a history of informing the Sanford police of questionable or suspicious activity in that gated community. He does not, as far as I can ascertain, have a history of violent confrontations, something community watch folks are warned against doing.
If you go to the City of Sanford’s online site, the telephone calls are all there as well as a report from the City Manager, Norton Bonaparte
http://www.sanfordfl.gov/index.html
http://www.sanfordfl.gov/investigation/docs/Zimmerman_Martin_shooting.pdf
actually, Zimmerman got in trouble several years ago for battery involving a police officer and his ex-fiance accused him of domestic abuse.