From a dispassionate reading of various news reports this certainly isn't a good shoot, but it doesn't appear to be a criminal one either. Mistakes were made all around by 911 operators, the officers and yes Tamir himself.
The real problem with this shooting and many others is that instead of a much needed review of policies that lead to these things happening, it will continue to be treated as a race thing. The fact is we have a lot of LEO interactions with all races that end up with officers being to quick to shoot or escalate violence. It has been created by courts not holding officers accountable, unions protecting bad cops, the thin blue line, the escalation of the war on drugs, even the so called militarization of Police is part of the problem. Of course in a lot of cases instead of common ground the left, right, and race warriors come at it all from different directions instead of saying we all have a problem we need to fix.