I cannot possibly understand how this dead boy was guilty of any crime. Knocking on a front door is not a capital offense. If you fear answering the door, don't answer it or peek out the window to see who is there before you open it. If you don't recognize the person, don't open the door or yell through the door for the person to identify himself.
There were too many common sense options available to this shooter before he opened fire. I'd put the shooter in prison if I was on the jury.
If the boy had broken into the house, I'd be with the shooter all the way.
I remember an incident when I was doing a sales presentation and I was nervous. I went back to my car to get some more materials and accidentally walked into the wrong house. Does that give someone the right to shoot me? I don't think so. There has to be some evidence of intent to harm the homeowner. Sometimes people pull pranks, accidentally knock on the wrong door, or even walk into the wrong house by accident. Looks like this homeowner was too eager to shoot somebody.
I own a bodyshop. At 11:30 pm one night, I heard a knocking at my front door. I jumped out of bed and grabbed a small .22 handgun. I answered the door. There was a black man standing there. The first thing he tried to do, was take a step into my house. I showed him my gun, and he was startled and stepped back. To make a long story short, it was a man I had given an estimate to , 2 weeks prior to this. He wanted to talk about fixing his car.
I told him to leave and find someone else to repair his car. No way I wanted to work on a guys car that would pull a stunt like this.