[fortran77]

It also seems that this is a little bit different from usual "lynch mobs" or vigilante justice because it was an act of self-defense. This man was going around shooting people and was actively making threats (though not at the exact moment he was shot).

This makes it a little more morally justified than shooting someone who committed some real or perceived wrong, but isn't a current threat to others.

They stopped him because he was dangerous.

[philwelch]

I think I’ve heard stories of eg battered wives killing their husbands and then claiming self-defense because they reasonably feared for their lives (and perhaps their children’s lives) in the long run.