Jim, your post reminds me of the case of Norfolk farmer Tony Martin, who shot dead a trespassing thief whom he found on his property. I believe it was a pair of travellers. (The other one wasn't shot) and they'd been trying to burgle him for ages. He was rather eccentric and lived all alone in a remote and isolated place.
Martin was jailed, but after three years his sentence was reduced and he was freed.

There was outrage on Martin's behalf, as there is now regarding a traveller knifed to death recently in a similar case where an elderly man and his wife who suffers from dementia were burgled and during a scuffle the traveller was killed. The elderly man was arrested, but later released.

I have mixed feelings about killing (either by shooting or knifing) a burglar. Obviously the miscreant shouldn't be in one's house in the first place stealing. And one shouldn't be expected to offer the chap a nice cup of tea and a slice of cake. Also, one would be terrified (I know I would!) and might attack in fear/self-defence. But anyone, burglar or not, losing their life is tragic. I can't bring myself to rejoice and say "Ha ha, Serves them right!" They are somebody's son/partner/dad after all.
I bet I'm alone in this over-sympathetic viewpoint (I always was a bit 'sorft' as they say in Norfolk)