” One of the criteria is if you can disengage and get away, there’s no justification for killing.” In my opinion, that’s a stupid criteria, since a member of the general public has just confirmed the individual is a threat to society, and should do us all a favor and make society that little bit safer. Has to be something lawyers came up with to keep themselves employed and feeding at the public tax dollars trough. My nickel’s worth (due to inflation).
Its because at that point you become a willing participant, when you could have just gotten away. Thats how the law views it. On a case by case basis people can and do find themselves in situations they couldn’t get away and thats the option thats employed, but its not a excuse to get revenge and commit murder if the deadly threat isn’t imminent and you can’t remove yourself from the situation. People of course can make their case for their decisions and very well may find the court/jury agrees.
Not every jurisdiction has “duty to retreat” laws. Many have “castle doctrine”.