How about justified homicide?
Let's start with training. Escalation training says if someone comes at you with a taser, you are supposed to use deadly force.
Let's move on to actions; man just spent 3 minutes beating on officers to get away, and took an officer's weapon.
Finally, let's talk the moments before death - another officer tried a less than lethal option, a taser, which failed to incapacitate the person under arrest who escaped custody. He was heading towards others after showing a willingness to use any weapon possible to escape police.
I don't know if he turned towards officers or not, honestly, to me, it doesn't matter. Clean shoot.