I don't have a horse in this race and I agree that it doesn't sound conclusive at all. They have someone screaming for help that was caught on a neighbor's call to police, presumably from indoors. They don't even have a sample of the victim to compare against the recording, so they're saying because it was only a 50% match, it must have been the other guy. Well, even if they had the other guy's voice, he might only be a 50% match too. receiver...
Plus, Z apparently told cops after the shooting (at the scene, is my understanding) that he was the one screaming for help. He'd have to be pretty sharp and with it (after he just shot a guy to death) to think to say that, knowing that it would be difficult for anyone to say that it was not him screaming, but the other guy, if that's what the truth is. And of course he would not have known there'd be a recording. I'm not an expert on the issue of how coherent people that kill people are after the event, and don't know his state of mind at the time, so maybe this is reaching or maybe it's not.
honestly, the media should stfu. All they're going to do is make it impossible to get an impartial jury, but maybe that is the point. i despise the media.