My Father(former Marine) once told me..."it is better to be Tried by 12, then Buried by 6"....which means it is better to be in court dealing with STOPPING A THREAT in your house with LETHAL FORCE, then to be dead because you didn't want to use LETHAL FORCE to stop the threat.
When it comes to safety of your family from "OVER PENETRATION" of ammo. You just have to know about the Personal Defense ammo you have in your weapon and know how much it penetrates(a Body, wall, door...ect). I would recommend Hornady Critical Defense ammo or Winchester PDX1 personal protection ammo, for handguns. If you have a Shotgun I would recommend 12gauge 00-Buck rounds 2/3in shells.
Home Defense is MUCH MORE then just owning a Gun, you have to know your weapon, and how to use it under STRESS. Also what ammo you are carrying in it, and how it reacts when fired.
STAY SAFE, and LONG LIVE THE SECOND AMENDMENT!
-GY6 @ www.youtube.com/GY6vids