IMHO, George Zimmerman stalked Trayvon Martin. If he hadn’t, nothing would have happened because Martin was simply walking home and was not engaged in any criminal activity, despite all the retroactive speculation and conjecture! Zimmerman was just not just minding his business. He decided that Martin was suspicious apparently based on his race and his attire (a hoodie).
More importantly, even after calling the police to investigate, he followed and monitored Martin, first in his car & then on foot (that could meet the definition “repeated”). Zimmerman was not a police officer and was admonished not to follow Martin by the police dispatcher. The rules of Neighborhood Watch also advised that volunteers were not to follow suspects or carry weapons . Zimmerman never identified himself. In fact, according to his own testimony, when Martin supposedly confronted him and asked if if he had a problem”, Zimmerman reached into his pocket.
Zimmerman had no authority whatsoever to follow Martin. Considering all that had occurred before, Martin would have been justified in seeing this as an aggressive act and that Zimmerman was reaching for a weapon. According to testimony at trial offered by Rachel Jeantel, Martin did view Zimmerman as a threat and had every right to feel threatened by Zimmerman’s behavior which not only including staring at him while in his care, following him on foot and then never identifying himself and reaching into his coat pocket quickly.
In a 2002 report the National Center for Victims of Crime defined stalking as “Virtually any unwanted contact between two people [that intends] to directly or indirectly communicates a threat or places the victim in fear can be considered stalking” although in practice the legal standard is usually somewhat stricter. https://en.wikipedia.org/wiki/Stalking
Zimmerman’s actions may not have constituted the crime of stalking under Florida law or they prosecution may not have decided to charge him. However, his actions and behavior was an aggressive act and led to the confrontation that caused Martin’s death. It would have been considered stalking by the looser definition espoused in the National Center for Victims of Crime standards.