This thread made me wonder what the 'recommended course of action' is in a situation like this. Here's what a Detective, who shall remain unnamed per his request, of the Fort Worth Police Department advised.
First, make sure he's ENTIRELY inside of your home. Do NOT drag him in, do not do it while he's halfway inside of the window, and do not do it if he's in your yard.
Second, shoot the bastard. (His words)
Third, if you put less than 3 rounds into him, shoot him again. It doesn't matter what caliber or gauge it is, put at least 3 rounds into the air. Apparently, killing someone with a single shot can qualify you as an 'expert' with this weapon to the court. This is a VERY bad thing. He also stated the ONLY exception to the '3 round' rule is if you're using a double barrelled shotgun, and then you need to empty both barrels.
Fourth, make sure he's dead. Once he's dead, get the hell away from him and call the police.
Fifth, practice saying "I feared for my life", "I feared for my family's safety", or something similar. Show either excessive emotion (tears, sniffles, huddling with your family, etc...) or complete numbness (no emotion at all, no feeling, like you can't believe you did it).
Sixth, expect to have your handgun confiscated. You might not be getting it back any time soon, depending on the city.
Seventh, go directly to the shop and purchase a replacement handgun.