You can be pro self defense and anti killing. If you have to kill someone, it means you have failed in every other attempt you could have made to accomplish your goals. The vast majority of people who might break into your house are just looking to steal. Are you going to justify ending the life of a person to protect a pile of stuff? There’s chemical irritants, light and sound based disorientation tools, tasers, and whole laundry lists of deterrents besides.

Im not saying any of those things are safe or foolproof, but killing a person to keep yourself safe should be a last resort.