It is murder if it is unjustified killing. He would have had no justification for killing had he not preset the situation. His words to the barber show he was deliberately setting up a situation IN ORDER to justify killing someone. That in itself removes all validity to that justification. Just as it is not legal for a concealed weapon carrier to start a fight and THEN claim he was in fear of his life when he drew and killed. He was only in fear for his life because he had put his life in danger. The man in this story was only justified by the robbery which he himself had invited. Not through negligence but through deliberate action. I can’t leave my car window down with an ipad on the seat and then wait behind the next car with a gun, to shoot whoever steals it. Beyond merely illegal it is grossly immoral. This man did not set out to defend his property. He deliberately put his property in danger (open garage door) in order to bait in someone to kill. he determined on his own volition that the robber was deserving of death and he then set up the situation whereby he would be able to administer it. Just because he did not know the kid by sight did not mean it wasn’t premeditated murder. He knew someone was robbing garages and he systematically planned and carried out a killing of that person. Had he not blabbed to the hairdresser he might have been able to make a case for justification (by lying or omitting his premeditation).
“Preset the situation”? No. Dede created the situation by going into the garage. Nobody goes into the garage, then no “situation”.
Equating this with starting a fight is mendacity.
And please don’t throw around the word “immoral” without describing which moral law was broken.