I don't want to add noise to the information here, but I do feel that one perspective has been overlooked. If your home is being invaded and you can fort up, being forted up and keeping 911 on the line seems to have worked in a few recent cases. This is especially true for the mother who held up in her bedroom and had 911 on the phone when the invader came crashing in causing her to kill him with the shotgun she was holding (this has been covered on the national news and many posts on this site and others). The other was is the report (a number of threads up from this one but in the Tactics forum) of the mother who had to fumble around looking for a weapon that she knew was around somewhere while her son, hiding in a closet, called 911 and got repeatedly disconnected. In either case, only a DA who was politically suicidal would have prosecuted. All this supposes that you can fort up in some room and maintain contact of some sort with 911.
This was the advice on an NRA video. Hold up if possible, inform 911 of your situation, location, and that you are threatened. Keeping 911 on the line while you loudly shout you have the police on the line, have a firearm, and will defend yourself were recommended. The view is that you now have evidence supporting your actions.