Depends on what source you believe. Some are saying there was a bench warrant out. Some are saying there were no warrants. Regardless, that is no justification for shooting him.
And while we're on the topic of dead unarmed suspects, have you caught the news out of Tulsa? Police catch man in sting selling them an illegal firearm. Suspect runs for it. Police chase man. Police catch man. During the attempt to subdue the suspect, part of the backup in the form of a seventy-three year old reserve Deputy comes up and shoots the suspect, killing him. The reserve Deputy claimed he was going for his tazer and grabbed his gun by mistake. Link
I'm sure folks around here will have no trouble justifying this one as well.
This is a huge taser problem. Remember the BART shooting a couple years ago. The officer actually says “Taser, taser, taser” then shoots the guy with his pistol. Many agencies have mandated cross draw for taser, but I would like to see a move towards weak hand draw.
Meserle made the same mistake at Fruitvale Station in Oakland 3 years ago and went to prison. Oscar Grant case. Not murder.