To the best of my knowledge, it varies state to state. My state is right on the edge and I had a uniformed Deputy tell me “iif you shoot someone on your front porch drag their body across the threshold before you call the police.” (He was joking but trying to make a point about the peculiarities of the law.) I think it has to do with your “duty to retreat“. If you can exit the situation safely you are required to leave instead of shooting the other person. Unless you were in your house. Your castle. Then you do not have a duty to retreat, even if you can do so safely. A couple of my friends took the NRA approved concealed carry class in my state and they said that it is thoroughly covered in the class. The information above is what they told me verbally. The information is out there and you shouldn’t have any problem looking it up on a state-by-state basis this is talked about regularly in the gun community. Edit; there are a few rules like do not say anything to the police. If you were the talkative type limit it to things like “oh my God I didn’t want to shoot him!” And “I thought he was going to kill me I was so scared.” No matter what questions they ask just repeat one of those two phrases. Or better yet say nothing. And, yes, you will spend at least a night in jail.