I did not think there was a state that you could legally shoot someone if you were not in fear for your life or someone else's.
I think you'll find plenty, including my state of Louisiana, where a person can use deadly force when he "reasonably believes that he is in imminent danger of losing his life or receiving great bodily harm."
[La. R.S. 14:20]
Specific verbiage will vary from state to state (maybe "great bodily injury," instead of "great bodily harm"), but the intent is the same. But clearly, in some jurisdictions, the threat doesn't have to rise to the level of "death."