Originally Posted by Colvin
Assume you believe that your neighbor is in danger- the scenario is unimportant.
Well, but that's different. The danger aspect is critical and broken windows probably don't meet the criteria.
Regardless, if the neighbor is in danger, it's not an "exception" to rules of self defense.
It is, in legal terms, not necessarily "self defense" anyway. It is " deadly physical force" and few, if any, laws in the USA make a particular distinction between using deadly physical force in defense of self versus others.
I have as much right to defend my neighbors life as I do my own. There might be (definately are) other legal complications that involve whether or not you really know what is happening or whether the "victim" might suddenly change their mind when you shoot their abusive husband... But those are separate questions.