Here's the main problem with the prosecution's case, as I see it.
- We know that Z watched TM.
- We know that he followed him (he was almost told to by one 911 dispatcher, when she instructed Z to "tell me if he does anything else"; but then was told that "we don't need you to" follow TM - in other words, 2 conflicting statements on the part of the dispatcher).
- We know that Z shot TM.
Pretty much anything beyond that is speculation, or testimony from only the defendant. The prosecution has presented no evidence that proves that Z started an altercation, that TM didn't "go for" Z's gun, that TM didn't violently endanger Z's life, or several other things.
The prosecution has a version of events that fits the evidence, and has filled in unverified acts that make sense. The defense has a different version of events that fit the evidence, and has filled in unverified acts that make sense.
Even if you were to determine guilt based upon which side you believed MORE, I'm not sure that you can chose the prosecution version over the defense version. When the burden on the prosecution increases to "beyond a reasonable doubt", I don't see how any fair and reasonable person can judge him guilty.