If it happened to me, with the benefit of hindsight, I might presume that the other person is attempting to demonstrate his dominance and trying to 'mark his territory':
The Territorial Imperative: A Personal Inquiry Into the Animals Origins of Property and Nations
by Robert Ardrey
http://www.amazon.com/books/dp/1568361440
... in the hope that I would be intimidated and go away.
If I were a neighborhood watch officer, this would put me on high alert. I would call the police and report the individual. I would try to assist the police in getting them to the scene as soon as reasonably possible by identifying the location. If I did not know the location, then I would consider it within my rights to get out of my car to try to find a street sign identifying the location.
T walking around the car is very suspicious but does not imply an imminent threat, though it does tend to indicate an attitude of belligerence.
I probably would have called 911 if the person seemed capable of overcoming me physically and had tapped on my car or tried to open it. I also would have called 911 if the person had made any belligerent verbal threats to me.
Admittedly this is a fine line, and I think there is some leeway on either side as to what the most appropriate thing to do would be. There is not always one right answer for what to do for every possible situation. In particular, if I were female with a relatively small physique, I would probably have felt more threatened and I would conceivably have dialed 911 immediately. However, the problem remains how to tell the police where I am. The police will require an address. If I do not provide an address, the police will not be able to locate me and arrive to help.
As I am a neighborhood watch officer, I do not at this time know all the streets in my neighborhood by heart. A part of my brain resists memorizing unneeded detail due to the rationalization that this is what street signs and maps are for. I do not think a person should be judged guilty simply because they rationalized that they would not need to be able to recall street names instantly. I do not associate guilt with having problems memorizing place names, even nearby place names. I believe anyone who does has unrealistic expectations.
Back to M, I think he was very emotionally troubled. M's father was bouncing him from home to home and had recently dumped the mother figure in his life for someone else. M might have felt a burden on his father's new girlfriend. Or M might have felt a need to overcompensate for his lack of feeling at home in the neighborhood. M might have resented his father and the rest of the world for some or all of these reasons. M might have resented his new family. It seems as if M did not have a key to the apartment. Was he aware that the girlfriend's son was not at home, so he was locked out in the rain? That would have pissed me off if I had been M. If M was under treatment for ADHD, aggression is a side effect of medical treatment for that problem. Maybe M thought Z was a threat to his masculinity and that he needed to overcompensate for that in an emotionally immature manner by circling M's car to demonstrate to Z with a show of force that M did not welcome Z in 'his' (M's) 'territory.' Etc.
I went back and found an article that said Tray was killed about 70 feet from his home. Wish I had a map and could see the reality of the situation.
Conjecture-
Somehow, Z’s appearance and presence in the neighborhood and his ‘following’ of M was a threat to M’s masculinity. By circling around Z’s car, M was daring Z to step out of the car and most likely inviting Z to get into a verbal or physical altercation. M was asserting his dominance over Z. By not stepping out of the car when M challenged Z in this way, Z was to M confirming his submission to M. At this time, though Z did not know it for certain, M had committed himself to getting rid of Z or physically beating him if Z stayed around and M ever saw him again.
Z, not feeling restrained by M’s show of aggression and dominance, waited until M was gone, then got out of the car to try to find out where he was to answer the police question. Z may have considered himself reasonably safe from M because either M had continued to his destination, or because none of the burglaries involved violence, might have been a non-violent burglar casing his next victim’s home.
Later, M found Z walking around M’s neighborhood (’territory’), apparently having ignored M’s challenge. From M’s perspective Z was ‘guilty’ of ignoring M’s warning to Z and deserving of a beatdown as punishment.
Both M and Z were asserting their dominance. M chose to assert his dominance with unlawful deadly physical force and was lawfully met with deadly force by Z.
Men are programmed to be dominant by thousands of years of evolution. Women are programmed to be submissive by the same evolutionary forces. Ordinarily women might have a difficult time relating to the mindsets of two men meeting at night in the rain and challenging each other for dominance. However, several of the women in this particular jury are married, so they are IMHO more likely to be sympathetic towards Z if the evidence suggests that the scenario as described above is what actually transpired between Z and M on the evening of M’s death. The exception- the unmarried female high level manager- is likely to be fairly intelligent by reason of her occupation, and so may be more likely than average to be able to put herself in Z’s position and reason based on hypothetical scenarios such as the above conjecture. Therefore the jury might favor Z, even though it is all female.