How to Defend Yourself - A shotgun Primer

They didn't specify what kind of ammo this homeowner used but at close range it could have been bird shot and still done the job.  The ideal is probably #3 or #4 buckshot but 00 is still what everyone hypes.    What you want is penetration and shock without over-penetration of walls.  00 can over-penetrate.

Homeowner defends his property.

If you want the means to defend yourself and your home then a 12 or 20 gauge pump shotgun will do the job.  You need to practice with it though.  Don't expect that if you point it in the general direction of your target that you'll hit it.   Check the spread pattern at 15 or 20 feet to see what I mean.  Put up a big cardboard box or a silhouette to see what a specific round of ammunition will do.  Don't leave it to chance.

The two best choices for a shotgun for home defense are the Mossberg 500 or the Remington 870.

20 gauge is less recoil so if you have someone that might be recoil sensitive expected to use it then go with a 20.

12 gauge is the mother of all firepower so think of that as the one you might choose if you are the only one to use it and you are familiar with recoil from shotguns.