There's a mathematical certainty that these thieves would've killed one of their victims in the future? Really is there a mathematical stat for this, that all career thieves kill at one point during their jobs? Again, then why don't you do our whole society a favor and go kill yourself some robbers, pimps, and whatever scumbags in this world?
You obviously wouldn't do it, but you applaud someone who clearly acted as judge, jury and executioner?
I think you're missing the point. I'm not saying these thieves don't deserve a beat down, or that Horn doesn't have a right to bear arms and protect himself. But it's the fact that HE HIMSELF WASN'T IN ANY DANGER. Hey, if those dead thieves decided to break into Horn's house right after they were done with his neighbor's then I could give two shits if Horn killed them in his front door, or as they were trying to climb through his window or whatever the fuck.