That scenario gets asked a lot by LE in training sessions and the answer is it is justified if it is shown beyond a reasonable certainty that the perp is an imminent danger to someone else if he gets away. His past actions are going to play a big part in determining this.

My opinion on the Atl shooting is that it hinges on a couple of issues. #1 Does Atl PD Policy and Procedures consider a taser a lethal use of force? The mayor seems to be flip flopping on this. If the P&P says it is not lethal force, then can the officer's defense team make a case that the perp would possibly come back and take his service weapon away from him while he was incapacitated? #2 Can the prosecution show beyond a reasonable doubt that the officer knew that was a taser and not a pistol that the perp pointed at him?

In my mind those are the questions that should make or break any case against the officer. I use the term should because it looks like his goose has already been cooked to serve at the sacraficial dinner. He won't get a fair trial in Atlanta.