Myself, the thieving punk would have been there for the cops one way or the other. I have worked way to hard for the things I own, and can't stand a thief.

"Bad guys you kill probably have even worse friends and relatives who won't see your side of the story, no matter how clear-cut it seems to you. The likelihood of retaliation problems would be greater, not less, if you had shot him."
This is a grey area to me. Kill or wound, or hold for the cops, and he might have friends willing to retaliate.
However, he might go back and get some friends after he escapes, to come back with him. 50/50 either way.
Again, I aint faulting you one bit on the way you handled it. Just giving another perspective.
Dan