OK, I'm going to paint a picture.
Zimmerman leaves his home, driving clockwise around Retreat View Circle, and stops at the crossing in front of the Clubhouse. On or about to use the crossing is Martin. Maybe he's dawdling or not moving fast enough for Zimmerman's liking. Zimmerman does not recognise him. Maybe they mutually eyeball each other, maybe not. Zimmerman see Martin head on to Twin Trees Lane, so he takes a snap decision to check this unknown youth out. He turns right onto Twin Trees Lane, perhaps driving slowly. As they pass, maybe their eyes meet (again), but either way Martin realises that the vehicle at the crossing now seems to be shadowing him, so he slows down a bit (more).
Zimmerman drives up to the crossing by the cut-through on Twin Trees Lane and stops, switching off his engine. He calls the police. He continues to watch for Martin, either by twisting around in his seat, or using his mirrors.
Martin now comes around the left hand bend in Twin Trees Lane, and sees that the mysterious vehicle has stopped about 75 metres ahead of him, but the driver is not getting out, and may appear to be watching him. Not quite sure what's going on, he may slow down more or even stop walking. He looks around to see if anyone else is about. The vehicle stays where it is, and Martin decides to carry on walking, but not too quickly, hoping the vehicle will drive off before he reaches it.
Zimmerman tells the police that the stranger is acting funny, "looking at all the houses," and then that he is, "coming to check me out."
Martin approaches the vehicle, then cuts across the crossing, and into the cut-through, speeding up in the knowledge that the vehicle can't follow, and the driver would have to get out and follow on foot. He calls his girlfriend.
Zimmerman tells the police that Martin is running, and gets out of his vehicle, following Martin, who he loses sight of behind the buildings as he (Martin) goes into the cut-through. He tells the police that Martin is heading for the "back entrance."
Martin turns onto the path between the houses. He knows he's about 150 metres from where he is staying, and can either run or hide. He choses the latter and manages to find some sort of cover.
Zimmerman comes in via the cut-through and looks down the wide gap between the houses, pausing for a few moments to satisfy himself that Martin is not running down there. Already convinced that Martin was already heading for the back entrance, he continues across the cut-through to Retreat View Circle, where he finds that Martin is not in sight there, either. Still on the phone to the police, he says he doesn't want to give him home address because, "I don't know where this kid is," i.e. he thinks he may be hiding within earshot. He stays where he is whilst directing to police to where his vehicle is. He ends the call to the police and then looks around some more to see if Martin is hiding, but doesn't see anything. He may actually walk some way down Retreat View Circle in this process.
Meanwhile, Martin - still on the phone to his girlfriend - is still hiding. He may have seen Zimmerman as he passed through to Retreat View Circle, but certainly cannot see him now. He doesn't tell his girlfriend he was hiding, because... well... he'll sound like a wimp. Eventually he convinces himself that Zimmerman is not coming back, so emerges from his hiding place.
Zimmerman, having satisfied himself that Martin is not anywhere on Retreat View Circle, heads back to his vehicle via the cut-through. In the process, he spots Martin again between the houses heading south to where is is staying, and approaches him. Martin either sees Zimmerman, because he keeps looking behind him to be sure, or he hears footsteps behind. He asks Zimmerman why he's following him. Zimmerman asks what he's doing there....